create triangles with for loops - examples (eugenp#7573)

catalin-burcea · KevinGilmore · commit 2c7c520a444e · 2019-08-18T21:35:36.000-05:00
diff --git a/algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/printtriangles/PrintTriangleExamples.java b/algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/printtriangles/PrintTriangleExamples.java
@@ -4,7 +4,7 @@
 
 public class PrintTriangleExamples {
 
-    public static String printARightAngledTriangle(int N) {
+    public static String printARightTriangle(int N) {
         StringBuilder result = new StringBuilder();
         for (int r = 1; r <= N; r++) {
             for (int j = 1; j <= r; j++) {
@@ -29,6 +29,17 @@ public static String printAnIsoscelesTriangle(int N) {
         return result.toString();
     }
 
+    public static String printAnIsoscelesTriangleUsingStringUtils(int N) {
+        StringBuilder result = new StringBuilder();
+
+        for (int r = 1; r <= N; r++) {
+            result.append(StringUtils.repeat(' ', N - r));
+            result.append(StringUtils.repeat('*', 2 * r - 1));
+            result.append(System.lineSeparator());
+        }
+        return result.toString();
+    }
+
     public static String printAnIsoscelesTriangleUsingSubstring(int N) {
         StringBuilder result = new StringBuilder();
         String helperString = StringUtils.repeat(' ', N - 1) + StringUtils.repeat('*', N * 2 - 1);
@@ -41,8 +52,9 @@ public static String printAnIsoscelesTriangleUsingSubstring(int N) {
     }
 
     public static void main(String[] args) {
-        System.out.println(printARightAngledTriangle(5));
+        System.out.println(printARightTriangle(5));
         System.out.println(printAnIsoscelesTriangle(5));
+        System.out.println(printAnIsoscelesTriangleUsingStringUtils(5));
         System.out.println(printAnIsoscelesTriangleUsingSubstring(5));
     }
 
diff --git a/algorithms-miscellaneous-3/src/test/java/com/baeldung/algorithms/printtriangles/PrintTriangleExamplesUnitTest.java b/algorithms-miscellaneous-3/src/test/java/com/baeldung/algorithms/printtriangles/PrintTriangleExamplesUnitTest.java
@@ -9,9 +9,9 @@
 
 @RunWith(JUnitParamsRunner.class)
 public class PrintTriangleExamplesUnitTest {
-    
-    private static Object[][] rightAngledTriangles() {
-        String expected0 = ""; 
+
+    private static Object[][] rightTriangles() {
+        String expected0 = "";
         
         String expected2 = "*" + System.lineSeparator() 
                          + "**" + System.lineSeparator();
@@ -39,9 +39,9 @@ private static Object[][] rightAngledTriangles() {
     }
 
     @Test
-    @Parameters(method = "rightAngledTriangles")
-    public void whenPrintARightAngledTriangleIsCalled_ThenTheCorrectStringIsReturned(int nrOfRows, String expected) {
-        String actual = PrintTriangleExamples.printARightAngledTriangle(nrOfRows);
+    @Parameters(method = "rightTriangles")
+    public void whenPrintARightTriangleIsCalled_ThenTheCorrectStringIsReturned(int nrOfRows, String expected) {
+        String actual = PrintTriangleExamples.printARightTriangle(nrOfRows);
 
         assertEquals(expected, actual);
     }
@@ -81,6 +81,14 @@ public void whenPrintAnIsoscelesTriangleIsCalled_ThenTheCorrectStringIsReturned(
 
         assertEquals(expected, actual);
     }
+
+    @Test
+    @Parameters(method = "isoscelesTriangles")
+    public void whenPrintAnIsoscelesTriangleUsingStringUtilsIsCalled_ThenTheCorrectStringIsReturned(int nrOfRows, String expected) {
+        String actual = PrintTriangleExamples.printAnIsoscelesTriangleUsingStringUtils(nrOfRows);
+
+        assertEquals(expected, actual);
+    }
     
     @Test
     @Parameters(method = "isoscelesTriangles")
