Javascript Bitwise Operator Left Shift

Introduction

The left shift is represented by two less-than signs (<<) and shifts all bits in a number to the left by the number of positions given.

For example, if the number 2 (which is 10 in binary) is shifted 5 bits to the left, the result is 64 (which is equal to 1000000 in binary), as shown here: 

let oldValue = 2;              // equal to binary 10 
let newValue = oldValue << 5;  // equal to binary 1000000 which is decimal 64

When the bits are shifted, five empty bits remain to the right of the number.

The left shift fills these bits with 0s to make the result a complete 32-bit number.

Note that left shift preserves the sign of the number it's operating on.

For instance, if -2 is shifted to the left by five spaces, it becomes -64, not positive 64.




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