Every computer language has operators.
JavaScript has following items:
There are two categories of operators. Binary: Two items (or operands) must be sandwiched on either side of the operator. Unary: onely one operand is required.
Arithmetic Operators
| Operator | Description | Example | Result |
|---|---|---|---|
| + | Addition | x=2 y=2 x+y | 4 |
| - | Subtraction | x=5 y=2 x-y | 3 |
| * | Multiplication | x=5 y=4 x*y | 20 |
| / | Division | 15/5 5/2 | 3 2.5 |
| % | Modulus (division remainder) | 5%2 10%8 10%2 | 1 2 0 |
| ++ | Increment | x=5 x++ | x=6 |
| – | Decrement | x=5 x– | x=4 |
Assignment Operators
| Operator | Example | Is The Same As |
|---|---|---|
| = | x=y | x=y |
| += | x+=y | x=x+y |
| -= | x-=y | x=x-y |
| *= | x*=y | x=x*y |
| /= | x/=y | x=x/y |
| %= | x%=y | x=x%y |
Comparison Operators
| Operator | Description | Example |
|---|---|---|
| == | is equal to | 5==8 returns false |
| === | is equal to (checks for both value and type) | x=5 y="5" x==y returns true |
| != | is not equal | 5!=8 returns true |
| > | is greater than | 5>8 returns false |
| < | is less than | 5<8 returns true |
| >= | is greater than or equal to | 5>=8 returns false |
| <= | is less than or equal to | 5<=8 returns true |
Logical Operators
| Operator | Description | Example |
|---|---|---|
| && | and | x=6 y=3 (x < 10 && y > 1) returns true |
| || | or | x=6 y=3 (x==5 || y==5) returns false |
| ! | not | x=6 y=3 !(x==y) returns true |
Operator Precedence
From lowest to highest
| Operator | Syntax |
|---|---|
| semicolon | ; |
| comma | , |
| assingment | =, +=, -=, *=, /=, %= |
| conditional | ?: |
| logical "or" | || |
| logical "and" | && |
| equality | ==, != |
| relational | <, <=, >, >= |
| mathematical | +, -, *, /, % |
| unary | !, -, ++, — |
| call | () |
