Method 1 :
var stringValue = "true";
var boolValue = (/true/i).test(stringValue) //returns true
Method 2 :
var stringValue = "true";
var boolValue = (stringValue =="true"); //returns true
Method 3 :
var stringValue = "true";
var boolValue = JSON.parse(stringValue); //returns true
Method 4 :
var stringValue = "true";
var boolValue = stringValue.toLowerCase() == 'true'; //returns true
Method 5 :
var stringValue = "true";
var boolValue = getBoolean(stringValue); //returns true
function getBoolean(value){
switch(value){
case true:
case "true":
case 1:
case "1":
case "on":
case "yes":
return true;
default:
return false;
}
}
source: http://codippa.com/how-to-convert-string-to-boolean-javascript/