Number.toLongString() method for extremely large values

Algorithm · 02-01-2003, 07:49 AM

Update 02-01-03: Changed as per recommendations.

The standard Number.toString() method returns values in scientific notation once they exceed 10^20. In many cases, this is not an expected or desired result.

The toLongString() method provides a solution by always returning a literal numeric value regardless of the number's size. However, the value returned will not be accurate beyond the first [log base (radix) of (10^15)] digits.

radix: Optional. A number between 2 and 36, inclusive.

Code:

Number.prototype.toLongString = function(){
    var radix, n = this, d, t = '', p = '';
    if(arguments.length>0 && typeof(arguments[0])=='number'){
        radix = Math.round(arguments[0]);
        if(radix<2) radix = 2;
        if(radix>36) radix = 36;
    } else {
        radix = 10;
    }
    if(n < 0){
        n *= -1;
        p = '-';
    }
    while(n > radix){
        d = n % radix;
        n = (n-d)/radix;
        t = d.toString(radix) + t;
    }
    return p + n.toString(radix) + t;
}

Alex Vincent · 02-01-2003, 07:05 PM

You'll get a JavaScript strict warning from that in Mozilla browsers.

http://www.javascriptkit.com/javatutors/serror.shtml

I'd suggest:

Code:

Number.prototype.toLongString = function(){
  if (arguments.length > 0) {
    var radix = arguments[0];
  } else {
    radix = 10;
  }
// ...

Algorithm · 02-01-2003, 08:26 PM

Good point. The necessary changes have been made.