IsNaN

From PlainOldWebserver

isNaN()

isNaN() determines whether a variable is a number.

 var a = "one";
 var b = "2";
 var c = 3;
 document.writeln("a isNaN: "+isNaN(a));
 document.writeln("b isNan: "+isNaN(b));
 document.writeln("c isNan: "+isNaN(c));

Result:

 a isNaN: true
 b isNan: false
 c isNan: false