How to call function jQuery

Question

I wanna callback jQuery function

$(function upload() {
.....
});
$("#select").change(function() {
 upload();
});

Console Uncaught ReferenceError: upload is not defined

Answer 1

You have actually provided a named callback to the shortcut DOM ready event handler. You need to declare it globally (or in the same scope).

This example has them in the same scope:

$(function(){ // DOM ready handler
 function upload() {
 };
 $("#select").change(function() {
 upload();
 });
});

As the function has no parameters it abbreviates to:

$(function(){ // DOM ready handler
 function upload() {
 };
 $("#select").change(upload);
});

The cleaner way (if the function is not reused) is just to place the code in the change callback:

$(function(){
 $("#select").change(function() {
 // Do the upload code here instead
 });
});

Answer 2

That is because it is inside a closure and therefore not global. Remove that $ wrapping and everything should be fine.

function upload() {
 // (...) code
}
$("#select").change(function() {
 upload();
})

Or put the <select> code inside the DOM ready wrapper. It should work too. Or declare it like

window.upload = function(){
 // this is global
}

Answer 3

You have to put ("#select").change inside Ready function and upload function outside ready function.

function upload() {
// any thing you want to do after select
};
$( document ).ready(function() {
$("#select").change(function() {
upload();
})
});

Answer 4

Try this : define a function upload inside $(function(){ }); and call it inside change event handler of select box.

$(function(){
 //define function
 upload = function(){
 ....
 }
 $("#select").change(function() {
 //call function
 upload();
 });
});

• iCollect.it Ltd: Actually your Note is incorrect. So long as it is defined in the same scope it will exist. Also it only needs to be defined before it is actually called. Javascript only checks at call-time :)
• Bhushan Kawadkar: @TrueBlueAussie, yeah you are correct.. I removed my note. Thanks :)