Given the following code:

What is `y`:

1. Index

2. Key

3. Index of key

4. Array

```var s = "Hello";

Indicate the type of each:

1. `s`

2. `x`

3. `s.toLowerCase()`

4. `s.toLowerCase`

5. `s.length`

6. `l`

Indicate whether this is an expression or a statement:

1. `l`

2. `l = 4;`

3. `l == 4`

4. `if (l == 4) { console.log("yes"); }`

5. `console.log("yes");`

6. `"yes"`

7. `console.log(l == 4 ? "yes" : "no")

How can you tell whether something is a statement?

How can you tell whether something is an expression

Bonus:

List all *statements* in the code above

List all *expressions* in the code above

Write code for the following:

1. Declare a variable called `x` and initialize it with the string "Hello".

2. Declare a variable called `y` and initialize it with the property `length` of `x`.

3. Declare a variable called `z` and initialize it with the result of calling the method `toUpperCase` on `x`