CODEWITHSUNDEEP
javascriptjquery
A Wizard Did It
A Wizard Did It

Reputation: 3674

Get variable passed to switch statement

This isn't the exact use scenario but I was wondering if it was possible to get the value passed to the switch statement without having to retype what is in the switch() part.

Example :

switch(someObject.withSomevalue*(Math.random()*11)) {
    case 1 : alert("one");
    // more cases here
    default: alert(theNumberThatWasPassed);
}

If we run the Math.random() again we'll get another random number that very well could meet one of the cases, so calling what aws called in the switch(x) statement isn't an option. I've been just storing it in a variable - x = someObject.withSomevalue*(Math.random()*11) - and then passing it to the switch that way switch(x), but I was wondering if it's possible to get the value passed to the switch within the switch statement.

Upvotes: 4

Views: 1133

Answers (5)

bugsmash
bugsmash

Reputation: 33

Interesting... OP, I'm trying to look at your thought process. Maybe just write out the code how you think it should look like (ignoring that it wouldn't work in the first place).

update:

At least in C/C++, you can just form another block to have the var only be accessible within the switch:


...
{
    var mySwitchVar = blah;
    switch(mySwitchVar) {
        case blah blah blah:
        default blah blah:
    }
}
...

Upvotes: 0

Vincent Ramdhanie
Vincent Ramdhanie

Reputation: 103145

As everyone else pointed out you have to save it in a variable. But you can do the following in the expression though I do not know how cross browser compatible this is:

  switch(x = <your expression>){
    //
    default:alert(x);
  }

and at least you save one line of code.

Upvotes: 5

Alin P.
Alin P.

Reputation: 44346

This is the same as asking if you can find the values for if(Math.random()){...}. The answer is no, because they are language constructs, and not functions.

Upvotes: 2

Justin Rassier
Justin Rassier

Reputation: 908

I would say your best bet would be to do what you currently are doing, and capture it into the variable before the switch statement. Is there any reason you would not want to do this besides saving a line of code?

Upvotes: 0

Kenny Wyland
Kenny Wyland

Reputation: 21880

Just capture it into a variable before the switch and use that variable.

var myValue = someObject.withSomevalue*(Math.random()*11);
switch(myValue) {
    case 1 : alert("one");
    // more cases here
    default: alert(myValue);
}

Upvotes: 2

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