Converting a line of String to an Int

Hi all, I want to know if it is possible to convert a line of string to an Int for example I,m reading from a Json file and it returns the Name and Nickname of a specific selected fighter but i want to count the amount of Nicknames the fighter has to use in a For loop ...

var tableInbox = Ti.UI.createTableView({ top:'6%', objName: 'tableInbox',bottom : '12%'});
var tableInboxData = [];
var url = 'https://raw.github.com/appcelerator/Documentation-Examples/master/HTTPClient/data/json.txt'; 
var xht = Ti.Network.createHTTPClient({
        onload:  function() {
        json = JSON.parse(this.responseText);
        Task = json.fighters[ID];  //The ID is the nr of the Name selected in the Array so it returns just 1name and its Nickname 
        alert(Task);
for (var i = 0; i < Task.Nickname.length ; i++){

If I use this code it counts all the fighters nicks and returns 10 insted of just the one and I know there is only 1 nick so a for loop is not necessary but this is just for the testing other data will replace the current Json and the code will be altered Thank you for the help