JQuery:

this.saveButton.click(function (e) {
    scope.saveForm();
});

This is a very simple line of JQuery that binds the .click() event to the saveButton object and calls a saveForm function when the event is fired.

When this event is called, what is 'e'? I don't think it is ever used.

JQuery:

this.saveButton.click(function (e) {
    scope.saveForm();
});

This is a very simple line of JQuery that binds the .click() event to the saveButton object and calls a saveForm function when the event is fired.

When this event is called, what is 'e'? I don't think it is ever used.

• javascript
• jquery

• 5 e is Euler's number, approximately equal to 2.7182818284 -- it's heavily used in logarithms and calculus. Your puter doesn't know this constant, which is why it is absolutely essential that you include it in all your event handlers, or risk exploding the entire Internet. – Blazemonger Commented Oct 12, 2011 at 14:00
• 2 Looking back on my ignorance years later. Priceless :) – contactmatt Commented Dec 11, 2014 at 0:12

4 Answers 4

The e can be used to obtain specific information about the click (left, right or center; coordinates clicked; DOM object clicked on), but this specific code sample doesn't use it.

See http://api.jquery./category/events/event-object/ for details about what's available.

It's the event object. Take a look at the documentation page here:

http://api.jquery./click/

Event handlers can take an optional parameter that contains information about the event that occurred. In this case, it is unused.

e (or any other name you use) is an Event object. It is very useful when you, for example want to determine where did the click event take place or which key was pressed on keydown event.

You should read this article on jQuery API.

Example usage:

$("#someInput").keydown(function (e) {
  alert(e.which) // alerts the keycode of the pressed key
});