Operators priority
Operator precedence determines the order in which operators in an expression are executed. There are a number of operators that have the same precedence. In this case, the order in which operators are executed is determined by the direction of computation, which is called associativity. The direction of evaluation for operators with equal precedence can be:
- from left to right;
- from right to left.
Below is a table of all JavaScript language operators in descending order of precedence.
| Priority | Operator | Associativity | Description |
|
0 |
( ) |
– |
Grouping |
|
1
|
[ ] . new |
From left to right From left to right – |
Access to the array item.
Access to the property. Creating an object with a list of arguments |
|
2
|
function
new |
From left to right From left to right |
Function call
Creating an object without a list of arguments |
| 3 | ++
— |
– – |
Postfix increment
Postfix decrement |
|
4
|
!
~ – ++ –– typeof void delete |
From right to left From right to left From right to left From right to left From right to left From right to left From right to left From right to left |
Logical negation
Bitwise logical negation Negation (negative number) Prefix increment Prefix decrement Type information Evaluate the expression and return undefined Deleting |
| 5 | *
/ % |
From left to right From left to right From left to right |
Multiplication
Division Remainder of the division |
| 6 | +
– |
From left to right From left to right |
Addition
Substraction |
| 7 | <<
>> >> |
From left to right From left to right From left to right |
Bitwise left shift
Bitwise right shift. Bitwise unsigned right shift. |
| 8 | <
<= > >= in instanceof |
From left to right From left to right From left to right From left to right From left to right From left to right |
Less
Less or equal More More or equal Checking if a property exists Type checking |
| 9 | ==
!= === !== |
From left to right From left to right From left to right From left to right |
Проверка на равенство
Checking for inequality Strict equality check Checking strict inequality |
| 10 | & | From left to right | Bitwise AND |
| 11 | ^ | From left to right | Bitwise exclusive OR (XOR) |
| 12 | | | From left to right | Bitwise OR |
| 13 | && | From left to right | Logical AND |
| 14 | || | From left to right | Logical OR |
| 15 | ?: | From right to left | Ternary conditional operator |
| 16 | =
+= -= *= /= %= <<= >>= >>> &= ^= != |
From right to left | Varieties of the assignment operator |
| 17 | yield | From right to left | Stopping and restoring a generator function |
| 18 | , | From left to right | Evaluates both operands and returns the value of the other |
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