Operators in JavaScript
Operators in JavaScript, as in PHP, can involve mathematics, changes to strings, and comparison and logical operations (and, or, etc.). JavaScript mathematical operators look a lot like plain arithmetic; for instance, the following statement outputs 16:
document.write(14 + 2)
The following sections teach you about the various operators.
Arithmetic Operators
| Operator | Description | Example |
|---|---|---|
| + | Addition | j+12 |
| – | Subtraction | j-22 |
| * | Multiplication | j*7 |
| / | Division | j/3.14 |
| % | Modulus (division remainder) | j%6 |
| ++ | Increment | ++j |
| — | Decrement | –j |
Comparison Operators
Comparison operators are generally used inside a construct such as an if statement where you need to compare two items. For example, you may wish to know whether a variable you have been incrementing has reached a specific value, or whether another variable is less than a set value, and so on.
| Operator | Description | Example |
|---|---|---|
| == | Is equal to | j == 42 |
| != | Is not equal to | j != 17 |
| > | Is greater than | j > 0 |
| < | Is less than | j < 100 |
| >= | Is greater than or equal to | j >= 23 |
| <= | Is less than or equal to | j <= 13 |
| === | Is equal to (and of the same type) | j === 56 |
| !== | Is not equal to (and of the same type) | j !== ‘1’ |
Logical Operators
Unlike PHP, JavaScript’s logical operators do not include and and or equivalents to && and ||, and there is no xor operator.
| Operator | Description | Example |
|---|---|---|
| && | And | j == 1 && k == 2 |
| || | Or | j < 100 || j > 0 |
| ! | Not | ! (j == k) |
