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However, both the "),s("a",{attrs:{href:"http://www.oracle.com/technetwork/java/codeconvtoc-136057.html",target:"_blank",rel:"noopener noreferrer"}},[t._v("Java Coding Convention"),s("OutboundLink")],1),t._v(" and the "),s("a",{attrs:{href:"https://google.github.io/styleguide/javaguide.html#s4.8.3.1-array-initializers",target:"_blank",rel:"noopener noreferrer"}},[t._v("Google Java Style Guide"),s("OutboundLink")],1),t._v(" discourage the form with brackets after the variable name—"),s("a",{attrs:{href:"http://docs.oracle.com/javase/tutorial/java/nutsandbolts/arrays.html",target:"_blank",rel:"noopener noreferrer"}},[t._v("the brackets identify the array type and should appear with the type designation"),s("OutboundLink")],1),t._v(". 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For example, an array with zero length like this is used for "),s("a",{attrs:{href:"http://stackoverflow.com/documentation/java/99/arrays/433/creating-an-array-from-a-collection",target:"_blank",rel:"noopener noreferrer"}},[t._v("Creating an "),s("code",[t._v("Array")]),t._v(" from a "),s("code",[t._v("Collection")]),s("OutboundLink")],1),t._v(" when the method needs the runtime type of an object.")]),t._v(" "),s("p",[t._v("In both primitive and reference types, an empty array initialization (for example "),s("code",[t._v("String[] array8 = new String[3]")]),t._v(") will initialize the array with the "),s("a",{attrs:{href:"http://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html",target:"_blank",rel:"noopener noreferrer"}},[t._v("default value for each data type"),s("OutboundLink")],1),t._v(".")]),t._v(" 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Therefore, this method of creating an array is best used only within the generic class - not exposed publicly.\n")])]),t._v(" "),s("li",[t._v("\nBy using "),s("a",{attrs:{href:"https://docs.oracle.com/javase/8/docs/api/java/lang/reflect/Array.html#newInstance-java.lang.Class-int-",target:"_blank",rel:"noopener noreferrer"}},[s("code",[t._v("Array.newInstance")]),s("OutboundLink")],1),t._v(" with a class parameter:"),s("p"),t._v(" "),s("div",{staticClass:"language-java extra-class"},[s("pre",{pre:!0,attrs:{class:"language-java"}},[s("code",[s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("public")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("MyGenericClass")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Class")]),s("span",{pre:!0,attrs:{class:"token generics"}},[s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("<")]),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("T")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(">")])]),t._v(" clazz"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),t._v("\n    a "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("T")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Array")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("newInstance")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("clazz"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("5")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),t._v("\n\n")])])]),s("p",[t._v("Here the class of "),s("code",[t._v("T")]),t._v(" has to be explicitly passed to the constructor. The return type of "),s("code",[t._v("Array.newInstance")]),t._v(" is always "),s("code",[t._v("Object")]),t._v(". 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These methods are passed a generator function which accepts an index and returns the desired value for that position.")]),t._v(" "),s("p",[t._v("The following example creates an integer array and sets all of its elements to their respective index value:")]),t._v(" "),s("div",{staticClass:"language-java extra-class"},[s("pre",{pre:!0,attrs:{class:"language-java"}},[s("code",[s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("int")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),t._v(" array "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("new")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("int")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("5")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n"),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Arrays")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("setAll")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("array"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" i "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("->")]),t._v(" i"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// The array becomes { 0, 1, 2, 3, 4 }.")]),t._v("\n\n")])])]),s("p",[s("a",{attrs:{href:"https://ideone.com/txh8Xv",target:"_blank",rel:"noopener noreferrer"}},[t._v("Live on Ideone"),s("OutboundLink")],1)]),t._v(" "),s("h3",{attrs:{id:"separate-declaration-and-initialization-of-arrays"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#separate-declaration-and-initialization-of-arrays"}},[t._v("#")]),t._v(" Separate declaration and initialization of arrays")]),t._v(" "),s("p",[t._v("The value of an index for an array element must be a whole number (0, 1, 2, 3, 4, ...) and less than the length of the array (indexes are zero-based). Otherwise, an "),s("a",{attrs:{href:"http://stackoverflow.com/documentation/java/99/arrays/512/arrayindexoutofboundsexception",target:"_blank",rel:"noopener noreferrer"}},[t._v("ArrayIndexOutOfBoundsException"),s("OutboundLink")],1),t._v(" will be thrown:")]),t._v(" "),s("div",{staticClass:"language-java extra-class"},[s("pre",{pre:!0,attrs:{class:"language-java"}},[s("code",[s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("int")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),t._v(" array9"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("             "),s("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// Array declaration - uninitialized")]),t._v("\narray9 "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("new")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("int")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("3")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("      "),s("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// Initialize array  - { 0, 0, 0 }")]),t._v("\narray9"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("0")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("10")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("           "),s("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// Set index 0 value - { 10, 0, 0 }")]),t._v("\narray9"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("1")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("20")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("           "),s("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// Set index 1 value - { 10, 20, 0 }")]),t._v("\narray9"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("2")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("30")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("           "),s("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// Set index 2 value - { 10, 20, 30 }")]),t._v("\n\n")])])]),s("h3",{attrs:{id:"arrays-may-not-be-re-initialized-with-array-initializer-shortcut-syntax"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#arrays-may-not-be-re-initialized-with-array-initializer-shortcut-syntax"}},[t._v("#")]),t._v(" Arrays may not be re-initialized with array initializer shortcut syntax")]),t._v(" "),s("p",[t._v("It is "),s("a",{attrs:{href:"http://docs.oracle.com/javase/specs/jls/se8/html/jls-10.html#jls-10.6",target:"_blank",rel:"noopener noreferrer"}},[t._v("not possible to re-initialize an array"),s("OutboundLink")],1),t._v(" via a shortcut syntax with an array initializer since an array initializer can only be specified in a field declaration or local variable declaration, or as a part of an array creation expression.")]),t._v(" "),s("p",[t._v("However, it is possible to create a new array and assign it to the variable being used to reference the old array. 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punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("collect")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Collectors")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("toList")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n\n")])])]),s("h3",{attrs:{id:"important-notes-related-to-using-arrays-aslist-method"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#important-notes-related-to-using-arrays-aslist-method"}},[t._v("#")]),t._v(" Important notes related to using Arrays.asList() method")]),t._v(" "),s("li",[t._v("\nThis method returns `List`, which is an instance of `Arrays$ArrayList`(static inner class of `Arrays`) and not `java.util.ArrayList`. The resulting `List` is of fixed-size. That means, adding or removing elements is not supported and will throw an `UnsupportedOperationException`:\n"),s("div",{staticClass:"language-java extra-class"},[s("pre",{pre:!0,attrs:{class:"language-java"}},[s("code",[t._v("stringList"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("add")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),s("span",{pre:!0,attrs:{class:"token string"}},[t._v('"something"')]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// throws java.lang.UnsupportedOperationException")]),t._v("\n\n")])])])]),t._v(" "),s("li",[t._v("\nA new `List` can be created by passing an array-backed `List` to the constructor of a new `List`. This creates a new copy of the data, which has changeable size and that is not backed by the original array:\n"),s("div",{staticClass:"language-java extra-class"},[s("pre",{pre:!0,attrs:{class:"language-java"}},[s("code",[s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("List")]),s("span",{pre:!0,attrs:{class:"token generics"}},[s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("<")]),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("String")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(">")])]),t._v(" modifiableList "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("new")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("ArrayList")]),s("span",{pre:!0,attrs:{class:"token generics"}},[s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("<")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(">")])]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Arrays")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("asList")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),s("span",{pre:!0,attrs:{class:"token string"}},[t._v('"foo"')]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token string"}},[t._v('"bar"')]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n\n")])])])]),t._v(" "),s("li",[s("p",[t._v("Calling `"),s("T",[t._v(" List"),s("T",[t._v(" asList(T... a)` on a primitive array, such as an\n`int[]`, will produce a `List"),s("int",{attrs:{"[]":""}},[t._v("` whose "),s("a",{attrs:{href:"http://stackoverflow.com/questions/2607289/converting-array-to-list-in-java"}},[t._v("only element is the source\nprimitive array")]),t._v(" instead of the actual elements of the source array.")])],1)],1)],1),t._v("\nThe reason for this behavior is that primitive types cannot be used in place of generic type parameters, so the entire primitive array replaces the generic type parameter in this case. In order to convert a primitive array to a `List`, first of all, convert the primitive array to an array of the corresponding wrapper type (i.e. call `Arrays.asList` on an `Integer[]` instead of an `int[]`).\nTherefore, this will print `false`:\n"),s("div",{staticClass:"language-java extra-class"},[s("pre",{pre:!0,attrs:{class:"language-java"}},[s("code",[s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("int")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),t._v(" arr "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("1")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("2")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("3")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("      "),s("span",{pre:!0,attrs:{class:"token comment"}},[t._v("// primitive array of int")]),t._v("\n"),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("System")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("out"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("println")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Arrays")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("asList")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("arr"),s("span",{pre:!0,attrs:{class:"token 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Below an example:")]),t._v(" "),s("div",{staticClass:"language-java extra-class"},[s("pre",{pre:!0,attrs:{class:"language-java"}},[s("code",[s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("int")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),t._v(" array "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("new")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("int")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("{")]),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("1")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("2")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("3")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("4")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("}")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\narray "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("ArrayUtils")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("removeElement")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("array"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("2")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token comment"}},[t._v("//remove first occurrence of 2")]),t._v("\n"),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("System")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("out"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("println")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Arrays")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("toString")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("array"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token comment"}},[t._v("//[1, 3, 4]")]),t._v("\n\n")])])]),s("h2",{attrs:{id:"how-do-you-change-the-size-of-an-array"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#how-do-you-change-the-size-of-an-array"}},[t._v("#")]),t._v(" How do you change the size of an array?")]),t._v(" "),s("p",[t._v('The simple answer is that you cannot do this.  Once an array has been created, its size cannot be changed.  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To do this, you will need to:")]),t._v(" "),s("ol",[s("li",[t._v("create a new array with size 4,")]),t._v(" "),s("li",[t._v("copy the existing 3 elements of the old array to the new array at offsets 0, 1 and 2, and")]),t._v(" "),s("li",[t._v("add the new element to the new array at offset 3.")])]),t._v(" "),s("p",[t._v("There are various ways to do the above.  Prior to Java 6, the most concise way was:")]),t._v(" "),s("div",{staticClass:"language-java extra-class"},[s("pre",{pre:!0,attrs:{class:"language-java"}},[s("code",[s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("String")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),t._v(" newArray "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("new")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("String")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),t._v("listOfCities"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("length "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("+")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("1")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n"),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("System")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("arraycopy")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("listOfCities"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("0")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" newArray"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("0")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" listOfCities"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("length"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\nnewArray"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),t._v("listOfCities"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("length"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token string"}},[t._v('"Sydney"')]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n\n")])])]),s("p",[t._v("From Java 6 onwards, the "),s("code",[t._v("Arrays.copyOf")]),t._v(" and "),s("code",[t._v("Arrays.copyOfRange")]),t._v(" methods can do this more simply:")]),t._v(" "),s("div",{staticClass:"language-java extra-class"},[s("pre",{pre:!0,attrs:{class:"language-java"}},[s("code",[s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("String")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),t._v(" newArray "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Arrays")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token function"}},[t._v("copyOf")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("(")]),t._v("listOfCities"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(",")]),t._v(" listOfCities"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("length "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("+")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token number"}},[t._v("1")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(")")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\nnewArray"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("[")]),t._v("listOfCities"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),t._v("length"),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v("]")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token string"}},[t._v('"Sydney"')]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(";")]),t._v("\n\n")])])]),s("p",[t._v("For other ways to copy an array, refer to the following example.  Bear in mind that you need an array copy with a different length to the original when resizing.")]),t._v(" "),s("ul",[s("li",[s("a",{attrs:{href:"http://stackoverflow.com/documentation/java/99/arrays/3435/copying-arrays#t=201610061130055885276",target:"_blank",rel:"noopener noreferrer"}},[t._v("Copying arrays"),s("OutboundLink")],1)])]),t._v(" "),s("h3",{attrs:{id:"a-better-alternatives-to-array-resizing"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#a-better-alternatives-to-array-resizing"}},[t._v("#")]),t._v(" A better alternatives to array resizing")]),t._v(" "),s("p",[t._v("There two major drawbacks with resizing an array as described above:")]),t._v(" "),s("ul",[s("li",[t._v("It is inefficient.  Making an array bigger (or smaller) involves copying many or all of the existing array elements, and allocating a new array object.  The larger the array, the more expensive it gets.")]),t._v(" "),s("li",[t._v('You need to be able to update any "live" variables that contain references to the old array.')])]),t._v(" "),s("p",[t._v("One alternative is to create the array with a large enough size to start with.  This is only viable if you can determine that size accurately "),s("strong",[t._v("before allocating the array")]),t._v(".  If you cannot do that, then the problem of resizing the array arises again.")]),t._v(" "),s("p",[t._v('The other alternative is to use a data structure class provided by the Java SE class library or a third-party library.  For example, the Java SE "collections" framework provides a number of implementations of the '),s("code",[t._v("List")]),t._v(", "),s("code",[t._v("Set")]),t._v(" and "),s("code",[t._v("Map")]),t._v(" APIs with different runtime properties.  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The following example snippets all assume that the array is one of the following:")]),t._v(" "),s("div",{staticClass:"language- extra-class"},[s("pre",{pre:!0,attrs:{class:"language-text"}},[s("code",[t._v('\n String[] strings = new String[] { "A", "B", "C" };\n  int[] ints = new int[] { 1, 2, 3, 4 };\n\n')])])]),s("p",[t._v("In addition, each one sets "),s("code",[t._v("index")]),t._v(" or "),s("code",[t._v("index2")]),t._v(" to either the index of required element, or "),s("code",[t._v("-1")]),t._v(" if the element is not present.")]),t._v(" "),s("h3",{attrs:{id:"using-arrays-binarysearch-for-sorted-arrays-only"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#using-arrays-binarysearch-for-sorted-arrays-only"}},[t._v("#")]),t._v(" Using "),s("a",{attrs:{href:"https://docs.oracle.com/javase/8/docs/api/java/util/Arrays.html#binarySearch-java.lang.Object:A-java.lang.Object-",target:"_blank",rel:"noopener noreferrer"}},[s("code",[t._v("Arrays.binarySearch")]),s("OutboundLink")],1),t._v(" (for sorted arrays only)")]),t._v(" "),s("div",{staticClass:"language- extra-class"},[s("pre",{pre:!0,attrs:{class:"language-text"}},[s("code",[t._v('\n int index = Arrays.binarySearch(strings, "A");\n  int index2 = Arrays.binarySearch(ints, 1);\n\n')])])]),s("h3",{attrs:{id:"using-a-arrays-aslist-for-non-primitive-arrays-only"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#using-a-arrays-aslist-for-non-primitive-arrays-only"}},[t._v("#")]),t._v(" Using a "),s("code",[t._v("Arrays.asList")]),t._v(" (for non-primitive arrays only)")]),t._v(" "),s("div",{staticClass:"language- extra-class"},[s("pre",{pre:!0,attrs:{class:"language-text"}},[s("code",[t._v('\n int index = Arrays.asList(strings).indexOf("A");\n  int index2 = Arrays.asList(ints).indexOf(1);  // compilation error\n\n')])])]),s("h3",{attrs:{id:"using-a-stream"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#using-a-stream"}},[t._v("#")]),t._v(" Using a "),s("code",[t._v("Stream")])]),t._v(" "),s("div",{staticClass:"language- extra-class"},[s("pre",{pre:!0,attrs:{class:"language-text"}},[s("code",[t._v('\n int index = IntStream.range(0, strings.length)\n                       .filter(i -> "A".equals(strings[i]))\n                       .findFirst()\n                       .orElse(-1); // If not present, gives us -1.\n  // Similar for an array of primitives\n\n')])])]),s("h3",{attrs:{id:"linear-search-using-a-loop"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#linear-search-using-a-loop"}},[t._v("#")]),t._v(" Linear search using a loop")]),t._v(" "),s("div",{staticClass:"language- extra-class"},[s("pre",{pre:!0,attrs:{class:"language-text"}},[s("code",[t._v('\n int index = -1;\n  for (int i = 0; i < array.length; i++) {\n      if ("A".equals(array[i])) {\n          index = i;\n          break;\n      }            \n  }\n  // Similar for an array of primitives\n\n')])])]),s("h3",{attrs:{id:"linear-search-using-3rd-party-libraries-such-as-org-apache-commons"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#linear-search-using-3rd-party-libraries-such-as-org-apache-commons"}},[t._v("#")]),t._v(" Linear search using 3rd-party libraries such as "),s("a",{attrs:{href:"https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/ArrayUtils.html",target:"_blank",rel:"noopener noreferrer"}},[t._v("org.apache.commons"),s("OutboundLink")],1)]),t._v(" "),s("div",{staticClass:"language- extra-class"},[s("pre",{pre:!0,attrs:{class:"language-text"}},[s("code",[t._v('\n int index = org.apache.commons.lang3.ArrayUtils.contains(strings, "A");\n  int index2 = org.apache.commons.lang3.ArrayUtils.contains(ints, 1);\n\n')])])]),s("p",[t._v("Note: Using a direct linear search is more efficient than wrapping in a list.")]),t._v(" "),s("h3",{attrs:{id:"testing-if-an-array-contains-an-element"}},[s("a",{staticClass:"header-anchor",attrs:{href:"#testing-if-an-array-contains-an-element"}},[t._v("#")]),t._v(" Testing if an array contains an element")]),t._v(" "),s("p",[t._v("The examples above can be adapted to test if the array contains an element by simply testing to see if the index computed is greater or equal to zero.")]),t._v(" "),s("p",[t._v("Alternatively, there are also some more concise variations:")]),t._v(" "),s("div",{staticClass:"language-java extra-class"},[s("pre",{pre:!0,attrs:{class:"language-java"}},[s("code",[s("span",{pre:!0,attrs:{class:"token keyword"}},[t._v("boolean")]),t._v(" isPresent "),s("span",{pre:!0,attrs:{class:"token operator"}},[t._v("=")]),t._v(" "),s("span",{pre:!0,attrs:{class:"token class-name"}},[t._v("Arrays")]),s("span",{pre:!0,attrs:{class:"token punctuation"}},[t._v(".")]),s("span",{pre:!0,attrs:{class:"token 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