Javascript boolean caster

gistfile1.js

/*
 * Convert values: 1, 0, true, false, "1", "0", "true", "false", "TRUE", "FALSE", "True", "False"
 * "ON", "OFF", "On", "Off", negative numbers, positive numbers, to booleans with a single JS line.
 * Easily extensible with new truthy values.
 */
 
function checkBool(val){
	return ({1:1,true:1,on:1,yes:1}[(((typeof val !=="number")?val:(val>0))+"").toLowerCase()])?true:false;
};