Operators

Operators take one or two values (or variables), perform an operation, and return a value. Let's check out a simple example of using an operator, just to clarify the terminology:

> 1 + 2;
3

In this code:

Instead of using the values 1 and 2 directly in the expression, you can use variables. You can also use a variable to store the result of the operation, as the following example demonstrates:

> var a = 1;
> var b = 2;
> a + 1;
2
> b + 2;
4
> a + b;
3
> var c = a + b;
> c;
3

The following table lists the basic arithmetic operators:

var a = 1; is also an operation; it's the simple assignment operation, and = is the simple assignment operator.

There is also a family of operators that are a combination of an assignment and an arithmetic operator. These are called compound operators. They can make your code more compact. Let's see some of them with examples:

> var a = 5;
> a += 3;
8

In this example, a += 3; is just a shorter way of doing a = a + 3;:

> a -= 3;
5

Here, a -= 3; is the same as a = a - 3;.

Similarly:

> a *= 2;
10
> a /= 5;
2
> a %= 2;
0

In addition to the arithmetic and assignment operators discussed previously, there are other types of operators, as you'll see later in this and the following chapters.