Left shifts the value of a variable by the number of bits specified in the value of an expression and assigns the result to the variable.
Using the <<= operator is exactly the same as specifying:
result = result << expression
The <<= operator shifts the bits of result left by the number of bits specified in expression. For example:
var temp temp = 14 temp <<= 2
The variable temp has a value of 56 because 14 (00001110 in binary) shifted left two bits equals 56 (00111000 in binary). Bits are filled in with zeroes when shifting.
Supported in the following document modes: Quirks, Internet Explorer 6 standards, Internet Explorer 7 standards, Internet Explorer 8 standards, Internet Explorer 9 standards. See Version Information.