Assignment Operators
An assignment operator assigns a value to its left operand based on the value of its right operand. The first operand must be a variable and basic assignment operator is equal (=), which assigns the value of its right operand to its left operand. That is, a = b assigns the value of b to a.
In addition to the regular assignment operator "=" the other assignment operators are shorthand for standard operations, as shown in the following table.
In addition to the regular assignment operator "=" the other assignment operators are shorthand for standard operations, as shown in the following table.
| Shorthand | Expression | Description |
|---|---|---|
| a +=b | a = a + b | Adds 2 numbers and assigns the result to the first. |
| a -= b | a = a - b | Subtracts 2 numbers and assigns the result to the first. |
| a *= b | a = a*b | Multiplies 2 numbers and assigns the result to the first. |
| a /=b | a = a/b | Divides 2 numbers and assigns the result to the first. |
| a %= b | a = a%b | Computes the modulus of 2 numbers and assigns the result to the first. |
| a<<=b | a = a<<b | Performs a left shift and assigns the result to the first operand. |
| a>>=b | a = a>>b | Performs a sign-propagating right shift and assigns the result to the first operand. |
| a>>>=b | a = a>>>b | Performs a zero-fill right shift and assigns the result to the first operand. |
| a&= b | a = a&b | Performs a bitwise AND and assigns the result to the first operand. |
| a^= b | a = a^b | Performs a bitwise XOR and assigns the result to the first operand. |
| a |=b | a = a|b | Performs a bitwise OR and assigns the result to the first operand. |
Bitwise Operators
Bitwise operators perform an operation on the bitwise (0,1) representation of their arguments, rather than as decimal, hexadecimal, or octal numbers. For example, the decimal number eight has a binary representation of 1000. Bitwise operators do their operations on such binary representation (for example 1000) but they return standard JavaScript numerical values.
Here is a list of JavaScript's bitwise operators.
| Operator | Usage | Description |
|---|---|---|
| Bitwise AND | a & b | Returns a one in each bit position if bits of both left and right operands are ones. |
| Bitwise OR | a | b | Returns a one in each bit if bits of either left or right operand is one. |
| Bitwise XOR | a ^ b | Returns a one in a bit position if bits of one but not both left and right operand are one. |
| Bitwise NOT | ~ a | Flips the bits of its operand. |
| Left shift | a << b | Shifts a in binary representation b bits to the left, shifting in zeros from the right. |
| Sign-propagating right shift | a >> b | Shifts a in binary representation b bits to the right, discarding bits shifted off. |
| Zero-fill right shift | a >>> b | Shifts a in binary representation b bits to the right, discarding bits shifted off, and shifting in zeros from the left. |
No comments:
Post a Comment