如何从jQuery事件函数返回变量值？

Question

Can I get value from jquery event function?

I want to get something like this:

function Init() {
    var my_variable = $some_object.click(function() {
         var my_variable = 'value';
         return my_variable // I need to get the variable value from click event
                            // but I don't know ways to do it
    });

    console.log(my_variable); // I want to have possibility to use the value here
}

Answer 1

No.

The function that sets the event handler will have finished running before the event handler runs.

Answer 2

No, you can't do that. You can only capture the value in a variable defined outside the scope of your handler:

function Init() {
    var my_variable = '';

    $some_object.click(function() {
         my_variable = 'value';
    });

    console.log(my_variable); //Prints empty string

    $some_object.trigger('click');

    console.log(my_variable); //Prints 'value'
}

Answer 3

The answer to your question is No!. You cannot return a value from event handler. Now next thing which made you curious is how to get some data which comes from the event handler itself. This is where event propagation comes and passing some data along with that.

Checkout below fiddle which shows how data which was created in event handler of button click, is being passed for any custom purpose.

http://jsfiddle.net/kowmwq9j/

Below is simple html and understandable javascript code

<div id='parent'>
    <button id='test'>CLick</button>
</div>

var a=document.getElementById('test');
a.addEventListener('click', function(){
   var str='sample';
   //creating a custom event with name 'build' and passing object as data
   var event = new CustomEvent('build', { 'detail': str });
   //dispatches the event which invokes the affected listeners
   this.dispatchEvent(event);
})

//Listening for 'build' event 
document.getElementById('parent').addEventListener('build', getData, true);

function getData(e){
  alert(e.detail);
}

Links shared which can help one to understand the concept. dispatchEvent & createCustomEvent .Hope that helps to answer your question! Added some comments & links which will help those who aren't aware of the functions & behavior used.

Answer 4

If I understand the question maybe you can do something like this...

Variable = 5 is used within 2 functions...each function does something with it's value...
the last function uses the totals of the first 2 functions and again does something..
So the point is that u can access the 2 totals variables and use them in the third function...
As long as you set your function variable as global...so don't put VAR in front of it.
If you set var in front of it u are saying that your variable is private for that function...

Change the value of the original variable and all the values changes ....

     variable = 5;                    // this is a global variable
     source = $('div#een h2');        // put your source here

    function Init(){
        source.on('click', function(){
          Total1 = variable * 2;

          console.log(Total1);  // It outputs 10
        });
    };

    Init();

    function Init2(){
     source.on('click', function() {
          Total2 = variable * 5;   

          console.log(Total2); // It outputs 25
      });
     };

    Init2();

    function Init3(){
      source.on('click', function() {
          Total3 = Total1 * Total2; // here we use the 2 Totals...

          console.log(Total3); // outputs the Total of both totals... should be 250
      });
     };

    Init3();