JS Assignment Operators - ashish9342/FreeCodeCamp GitHub Wiki
Assignment operators, as the name suggests, assign (or re-assign) values to a variable. While there are quite a few variations on the assignment operators, they all build off of the basic assignment operator.
x = y;
| Description | Necessity
--------- | --------------------------------------------- | --------- x | Variable | Required = | Assignment operator | Required y | Value to assign to variable | Required
let initialVar = 5; // Variable initialization requires the use of an assignment operator
let newVar = 5;
newVar = 6; // Variable values can be modified using an assignment operator
The other assignment operators are a shorthand for performing some operation using the variable (indicated by x above) and value (indicated by y above) and then assinging the result to the variable itself.
For example, below is the syntax for the addition assignment operator:
x += y;
This is the same as applying the addition operator and reassigning the sum to the original variable (i.e., x), which can be expressed by the following code:
x = x + y;
To illustrate this using actual values, here is another example of using the addition assignment operator:
let myVar = 5; // value of myVar: 5
myVar += 7; // value of myVar: 12 = 5 + 7
Operator | Syntax | Long version |
---|---|---|
Assignment | x = y | x = y |
Addition assignment | x += y | x = x + y |
Subtraction assignment | x -= y | x = x - y |
Multiplication assignment | x *= y | x = x * y |
Division assignment | x /= y | x = x / y |
Remainder assignment | x %= y | x = x % y |
Exponentiation assignment | x **= y | x = x ** y |
Left shift assignment | x <<= y | x = x << y |
Right shift assignment | x >>= y | x = x >> y |
Unsigned right shift assignment | x >>>= y | x = x >>> y |
Bitwise AND assignment | x &= y | x = x & y |
Bitwise XOR assignment | x ^= y | x = x ^ y |
Bitwise OR assignment | x | = y |