JSFiddle - React, Tailwind, and code Playground

by Darby Rathbone

JavaScript

function add(A, B) {
    if (A.split('').length > B.split('').length) {
        var a = A,
            b = B;
    } else {
        var b = A;
        var a = B;
    }
    _a = a.split('').reverse(),
    _b = b.split('').reverse('');
    var sol = _a.map(function (e, i, ar) {
        var v = (parseInt(e) + (parseInt(_b[i]) || 0));
        if (i + 1 === ar.length) return v;
        if (v > 9) _b[i + 1] = parseInt(_b[i + 1]) + 1;

        return v % 10;
    }).reverse().join('');
    return sol;
}
function subtract(A,B){
    var a = A.split('');   
    var b = B.split('');
    var count = Math.max(a.length,b.length)Math.min(a.length,b.length);
    while(count--)
    {
           if (a.length < b.lenght)
               a.unshift('0');
           else
               b.unshift('0');
    }
    console.log(a,b);
}
subtract("12351232","123");