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JavaScript jQuery Basics (2014) Creating a Simple Drawing Application Perform: Part 2

Lucian Dumitru
PLUS
Lucian Dumitru
Courses Plus Student 13,024 Points
Posted by Lucian Dumitru
Lucian Dumitru
Courses Plus Student 13,024 Points

Why aren't you using parentheses when calling the changeColor() function ?

Considering the following line of code:

$("input[type=range]").change(changeColor);

Why is he using

.change( changeColor ); //the function is called without parentheses

and not 

.change( changeColor() );

Can someone explain? I'm a little bit confused.

1 Answer

Steven Parker
Steven Parker
231,269 Points
Steven Parker
Steven Parker
231,269 Points

The function is not being called.

In this case, the function itself, and not the result of calling it, is being passed as a parameter to establish an event handler. It will be invoked later by the system when a change event occurs on range input element.

Functions used this way are often called callback functions.