How can I make jquery wait for one function to finish before executing another function?

Question

function test(){
var distance=null;
       first();
       second();
       third();
alert(distance);//it shows null always because it take 2 second to complete.

}
 fun         


        

Answer 1

Make use of callbacks:

function first(tolat, tolon, fromlat, fromlon, callback) {
     if (typeof(callback) == 'function') {
        callback(distance);
     }
}

function second() { }
function third() { }

first("vartolat", "vartolon", "varfromlat", "varfromlon", function(distance) {
    alert(distance);
    second();
    third();
});