Extending Javascript objects

Demonstrates simplicity in extending Javascript objects

by Ron Eaglin

HTML

<h1>Extending Javascript object</h1>
<input type="textbox" id="a" value="45"/>
<input type="textbox" id="b" value="30"/>
<input type="button" value="Calculate GCD" onClick="calculate();" />
<div id="Results"></div>

JavaScript

Math.GCD = function(a,b) {
    if (a < 0) a = -a;
    if (b < 0) b = -b;
    if (b > a) {var temp = a; a = b; b = temp;}
    while (true) {
        a %= b;
        if (a == 0) return b;
        b %= a;
        if (b == 0) return a;
    }
}

Math.LCM = function(a,b) {
    return a * (b / this.GCD(a, b));
}

function calculate() {
    
  var a = document.getElementById("a").value;
  var b = document.getElementById("b").value;
  var c = Math.GCD(a,b);
  var d = Math.LCM(a,b);
  document.getElementById("Results").innerHTML 
  = "<br/>GCD: " + c + "<br/>LCM: " + d;  
}