Run two functions with Ajax calls sequentially

Question

I have two functions which has ajax calls inside them.

function a(){
    ajaxCall_A();
}
function b(){
    ajaxCall_B();
}

And I

Answer 1

Simply use jQuery.when() & done() with Deferred:

    function a() {
        var deferred = $.Deferred();

        $.ajax({
        url: "url_a",
        type: "post",
        dataType: "html",               
        cache: false,
        success: function(data){             
            deferred.resolve(data);
        },
        error:function(){             
           deferred.resolve("Error from a()");
       }   
      });  
      return deferred.promise();
    }
    function b() {
        var deferred = $.Deferred();

        $.ajax({
        url: "url_b",
        type: "post",
        dataType: "html",               
        cache: false,
        success: function(data){             
            deferred.resolve(data);
        },
        error:function(){             
           deferred.resolve("Error from b()");
       }   
      }); 

        return deferred.promise();
    }

    function c()
    {
        $.when(
            a(),
            b()
       )
      .done(function ( v1, v2 ){
      //Do your work - v1 and v2 are resolved value from a() and b() 
      });       
    }