toggle passed in variable boolean value in javascript function

Question

I would like to create a re-usable function that changes the boolean value of the variable that is passed in.

My example is below however this doesn't work as the first part of the statement 'item' is not assigned to the variable passed in.

let editable = true;

     function toggleEditMode (item){
            item = !item;
        }

toggleEditMode(editable);

Any help?

I updated the link. Read new one.

cmac
– cmac

2017-03-30 11:37:52 +00:00
Commented Mar 30, 2017 at 11:37 — cmac
– cmac, Commented Mar 30, 2017 at 11:37
did that solve your problem?

cmac
– cmac

2017-03-30 11:54:41 +00:00
Commented Mar 30, 2017 at 11:54 — cmac
– cmac, Commented Mar 30, 2017 at 11:54
This worked. @cmac

Sachin Karia
– Sachin Karia

2017-03-30 13:59:26 +00:00
Commented Mar 30, 2017 at 13:59 — Sachin Karia
– Sachin Karia, Commented Mar 30, 2017 at 13:59

Community · Accepted Answer · 2017-05-23 11:46:24Z

3

You have to learn how js passes function arguments. It is passing by value here. Read this by value vs reference

Basically you can't pass by reference like you are trying to. You can make an object and then change a property on that object inside your function and it will work how you are expecting.

var i = { a:true }

function c(o){
  o.a = !o.a
}

c(i)
console.log(i);

edited May 23, 2017 at 11:46

CommunityBot

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answered Mar 30, 2017 at 11:33

cmac

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2 Comments

cmac Over a year ago

@PankajParkar I was putting together example code for him just moving little slow cause on iPhone not in front of computer. ;)

Sachin Karia Over a year ago

yes this worked, I thought there might've been a cleaner solution without using objects, thanks.

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