How to convert binary fraction to decimal

Question

Javascript has the function parseInt() which can help convert integer in a binary form into its decimal equivalent:

parseInt(\"101\", 2) // 5
         


        

Answer 1

You can create javascript extension method like parseInt as I have created method parseBinary which works just link parseInt.

String.prototype.parseBinary = function parseBinary() {
  var radix = 2;
  var s = this.split('.');
  var decimal = parseInt(s[0], radix);

  if(s.length > 1){
    var fract = s[1].split('');

    for(var i = 0, div = radix; i < fract.length; i++, div = div * radix)
    {
      decimal = decimal + fract[i] / div;
    }
  }
  return decimal;
};

To use this method you can call it using following code.

var str = "0.101";
alert(str.parseBinary());

Here is a working example of javascript code

String.prototype.parseBinary = function parseBinary() {
  var radix = 2;
  var s = this.split('.');
  var decimal = parseInt(s[0], radix);

  if(s.length > 1){
    var fract = s[1].split('');

    for(var i = 0, div = radix; i < fract.length; i++, div = div * radix)
    {
      decimal = decimal + fract[i] / div;
    }
  }
  return decimal;
};

var str = "0.101";
alert(str.parseBinary());