Assignment Operators

An assignment operator assigns a value to its left operand based on the value of its right operand. The most common assignment operator is = , which just assigns the value of an expression to a variable, like this line of code we've already seen:

 var kilograms = pounds / 2.2046 

The other assignment operators are shorthand assignment operators . How do they work? If you want to add one to a value, you can do so as follows :

 todaysDate = todaysDate + 1 

However, using the += shorthand operator, you can do this a little easier, like this:

 todaysDate += 1 

In other words, the statement todaysDate = todaysDate + 1 does the same thing as the statement todaysDate += 1 . You can use either in your code. Table 2.6 lists the JavaScript shorthand assignment operators.

Table 2.6. JavaScript Shorthand Assignment Operators

Shorthand Operator	Is the Same As
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
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
x = y	x = x y