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JavaScript Introduction to jQuery Events Event Types

Posted by Yuval Blass
Yuval Blass
18,134 Points

Arrow functions - jQuery

Why isn't it working?

$('.loc').hover( () => {
  $(this).html("<strong>Location:</strong> your House?!");
}, () => {
  $(this).html("<strong>Location:</strong> Treehouse Adoption Center");
});

And when I change the arrow function... Why is it working?

$('.loc').hover( function() {
  $(this).html("<strong>Location:</strong> your House?!");
}, function() {
  $(this).html("<strong>Location:</strong> Treehouse Adoption Center");
});
Max Karacsony
Max Karacsony
23,928 Points
Max Karacsony
Max Karacsony
23,928 Points

The difference is the this binding of the arrow function. By using an arrow function this is not the element you hover and so no html can be set on it. See this blog post: https://rainsoft.io/when-not-to-use-arrow-functions-in-javascript/ The second point describes your example.

2 Answers

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

Arrow functions are not exact replacements for conventional functions.

There are several things conventional functions define for you that arrow functions do not, like arguments and as Max pointed out, this.

You can still use them as event handlers, but pass the event object to them and use its target property instead of this:

$('.loc').hover( e => {
  $(e.target).html("<strong>Location:</strong> your House?!");
}, e => {
  $(e.target).html("<strong>Location:</strong> Treehouse Adoption Center");
});
Yuval Blass
Yuval Blass
18,134 Points
Yuval Blass
Yuval Blass
18,134 Points

Max Karacsony Steven Parker Thanks