这个方法不是更快，但它相当原生。

zeroPad = function (num, count) {
    return [Math.pow(10, count - num.toString().length), num].join('').substr(1);
};

一些monkeypatching也可以工作

String.prototype.padLeft = function (n, c) {
  if (isNaN(n))
    return null;
  c = c || "0";
  return (new Array(n).join(c).substring(0, this.length-n)) + this; 
};
var paddedValue = "123".padLeft(6); // returns "000123"
var otherPadded = "TEXT".padLeft(8, " "); // returns "    TEXT"

ECMAScript 2017: 使用padStart或padEnd

'abc'.padStart(10);         // "       abc"
'abc'.padStart(10, "foo");  // "foofoofabc"
'abc'.padStart(6,"123465"); // "123abc"

更多信息:

https://github.com/tc39/proposal-string-pad-start-end https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/padStart

还有另一个版本:

function zPad(s,n){
    return (new Array(n+1).join('0')+s).substr(-Math.max(n,s.toString().length));
}

可变长度填充功能:

function addPaddingZeroes(value, nLength)
{
    var sValue = value + ''; // Converts to string

    if(sValue.length >= nLength)
        return sValue;
    else
    {
        for(var nZero = 0; nZero < nLength; nZero++)
            sValue = "0" + sValue;
        return (sValue).substring(nLength - sValue.length, nLength);
    }
}

function zFill(n,l){
    return 
      (l > n.toString().length) ? 
        ( (Array(l).join('0') + n).slice(-l) ) : n;
}