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JavaScript DOM Scripting By Example Adding and Removing Names RSVP Checkbox

Posted by Zhenghao He
Zhenghao He
Courses Plus Student 2,389 Points

consistency between (e)=> {} and event.

The teacher first used

ul.addEventListener('change',(e)=>{ 
  console.log(e.target.checked);
})```
to log out the information then he used 
```ul.addEventListener('change',(e)=>{
  const checkbox = event.target;
  const checked = checkbox.checked;
  const listItem = checkbox.parentNode.parentNode;
  if (checked) {
    listItem.className = 'responded'
  } else {
    listItem.className = ''
  }})

I mean why don't he try to make it consistent by using

``` const checkbox = e.target;

or 
```ul.addEventListener('change',(event)=>{```

2 Answers

Steven Parker
Steven Parker
229,708 Points
Steven Parker
Steven Parker
229,708 Points

I'd guess it was unintentional. It might even qualify as a "bug" in the course. If you consider it so, you may want to report it to the staff as described on the Support page.

It probably didn't get noticed because many browsers establish a global "event" variable which is equal to the event object of the current event.

Zhenghao He
Zhenghao He
Courses Plus Student 2,389 Points

thanks Steven. Can you please take a look at this question as well https://teamtreehouse.com/community/how-do-i-achieve-button-smooth-background-transition-on-mobile-device

lee ellis
lee ellis
8,430 Points
lee ellis
lee ellis
8,430 Points

Mixing these didnt work in my browser, i had to change this to match otherwise no styling would show around the checkbox (using firefox).

Bozhong Tao
Bozhong Tao
18,365 Points
Bozhong Tao
Bozhong Tao
18,365 Points

the same here, tested on firefox 59.0.2 (64-bit) had to change to 'const checkbox = e.target;' Otherwise I get a reference error: "ReferenceError: event is not defined"