Number.toString(2) is omitting 0's from end in javascript?

Question

I am trying to reverse the 32-bit unsigned integer by converting it to a string first but the toString(2) function is committing the zero's from the end and because of it the output I am getting is wrong.

MyCode:

var reverseBits = function(n) {
    let reverserN=(n>>>0).toString(2).split('').reverse().join('');
    console.log(reverserN)
    
    return parseInt(reverserN,2)
};

Output:

Your input 00000010100101000001111010011100

stdout 00111001011110000010100101 //0's omitted from the end

Output 15065253 (00000000111001011110000010100101)

Expected 964176192 (00111001011110000010100101000000)

And, if I try to use BigInt then it is giving me n at the end. Like this 00111001011110000010100101n.

Why 0's are omitted? And how can I stop it from omitting 0's from the end?

Answer 1

By adding padEnd(32,0) after join('') works. Which simply added 0's at the end to the resulting string so that it reaches a given length.

Mycode:

var reverseBits = function(n) {
    let reverserN=(n>>>0).toString(2).split('').reverse().join('').padEnd(32,0);
    console.log(reverserN);
    return parseInt(reverserN,2)
};

Output:

00111001011110000010100101000000 //6 0's at the end of the string