Why does default case also run in a switch case fall though in javascript

Asked Oct 12 '21 at 15:15

Active Oct 12 '21 at 15:20

Viewed 15 times

Following is my javascript code:-

var time = 21
var text;
switch (time) {
  case 21:
    text = "1st case";
  case 22:
    text = "2nd case";
  case 23:
    text = "3rd case";
  default:
    text = "default";
}
console.log(text);

In the above code I wanted to know in line 9 and 11, why does this default statement also run and changes the text variable to "default"?

I wanted a little bit detailed explanation for this, according to my knowledge and a bit of gathering information I found that this will follow the rule of fall through, but I wanted to know why... or maybe there is another breakdown to this code.

NOTE - Removing break statement was intentional.

edited Oct 12 '21 at 15:20

T.J. Crowder

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asked Oct 12 '21 at 15:15

Soham Verma

2

Missing `break;` statements. – VLAZ Oct 12 '21 at 15:16
Removing break was intentional – Soham Verma Oct 12 '21 at 15:17
1

Well, you also get the intended behaviour for code without `break;` statements. – VLAZ Oct 12 '21 at 15:18
1

Please don't do the over-the-top formatting thing. Just post your question with normal text. – T.J. Crowder Oct 12 '21 at 15:19
Why does it run the default statement also? shouldn't it just stop at the last case as we already have an answer? – Soham Verma Oct 12 '21 at 15:20
2

"Removing break was intentional" - well, you wanted fallthrough, you got fallthrough. – Sergio Tulentsev Oct 12 '21 at 15:20
Is there a specific reason why the default case runs or it just just how javascript works...? – Soham Verma Oct 12 '21 at 15:22
It's how pretty much all languages with a `switch` statement work. Java, C, C++, C#, etc. – VLAZ Oct 12 '21 at 15:23
All of this is discussed in [the MDN documentation](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/switch). – Andy Oct 12 '21 at 15:28
Okay understood, this question was given to me by my professor, and just to confirm I asked this question. – Soham Verma Oct 12 '21 at 15:28
There's nothing special about the default cause with respect to fall-through. Just think of it as a shortcut for listing all the other cases. – Barmar Oct 12 '21 at 15:49

Why does default case also run in a switch case fall though in javascript

0 Answers0