A switch statement doesn't work when the equivalent if statement does

Question

switch(type)
{
    case 'home':
         console.log('home switch');
         break;
}

The above code does not write out to the console, neither does the following:

switch(type)
{
     case "home":
         console.log('home switch');
         break;
}

The following, however, does:

if (type == 'home')
{
     console.log('home if');
}

I don't have a clue why. This isn't a show-stopper, I can use the if statement instead, but I'm genuinely curious as to why this is the case.

NOTE: These statements are a straight replace, nothing else to consider here. No change in scope, no code I'm not mentioning that could be interfering with the value of type.

what is the exact value of type, are u putting value in type dynamically? — Laxmikant Dange, May 02 '14 at 14:12
Are you actually using the string `home`? or is it really a different value? — epascarello, May 02 '14 at 14:15
I copied your code exactly into the Firebug console and set `type = "home"`, as you stated, and it fired the `console.log()` statement in all three instances. Have you tried checking out `console.log(type)` right before the `switch` to see what the value is? — talemyn, May 02 '14 at 14:18
since each case is an executed expression, you can easily "overload" switch to do any kind of compare: switch(true){ case type=="home" : ... } — dandavis, May 02 '14 at 15:27

score 8 · Accepted Answer · answered May 02 '14 at 14:12

8

That's not the equivalent if-statement. The switch statement is specified to use the strict equality === operator.

answered May 02 '14 at 14:12

Bergi

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I didn't realize this. I've just changed my `if` to use `===` and, as you'd expect, it hasn't met the condition. I don't really understand what's happened here though, it's merely a string - surely `===` would be satisfied? If not, how else do you switch case a string? – May 02 '14 at 14:14
@DeeMac: Looks like it's not then. Please make a demo with an example value for `type`. Also test `console.log(typeof type)`. – Bergi May 02 '14 at 14:15
1

This is not a solution to OP question but i learned something today! – laaposto May 02 '14 at 14:16
You might try `switch(String(type)) { … }` then. – Bergi May 02 '14 at 14:17
@laaposto: Until the OP shows more of his code, I cannot offer a "solution". It does answer the question "*I don't have a clue why*" though :-) – Bergi May 02 '14 at 14:19

A switch statement doesn't work when the equivalent if statement does

1 Answers1