javascript - Can a mathematical operator be used in a switch expression? - Stack Overflow

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I'm having a problem using a mathematical operator in a switch expression.

This is what my code currently looks like:

var x = 18;
var y = 82;

var result = x + y;

switch(result) {
case "200":
document.write("200!");
break;
case "500":
document.write("500!");
break;
case "100":
document.write("100! :)");
break;
default:
document.write("Something's not right..");
}

Explained: the variable "result" has a value of 100. I am trying to use that value with the switch operator, but it just isn't working.

I've also tried using the equation itself as the switch expression, but that doesn't work either.

P.S: I just started out with JavaScript. Bet I missed something obvious...

I'm having a problem using a mathematical operator in a switch expression.

This is what my code currently looks like:

var x = 18;
var y = 82;

var result = x + y;

switch(result) {
case "200":
document.write("200!");
break;
case "500":
document.write("500!");
break;
case "100":
document.write("100! :)");
break;
default:
document.write("Something's not right..");
}

Explained: the variable "result" has a value of 100. I am trying to use that value with the switch operator, but it just isn't working.

I've also tried using the equation itself as the switch expression, but that doesn't work either.

P.S: I just started out with JavaScript. Bet I missed something obvious...

• javascript
• switch-statement

Share Improve this question Follow asked Oct 30, 2011 at 19:50 SweelySweely 39644 silver badges1717 bronze badges

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3 Answers 3

Sorted by: Reset to default 5

Change "100" to 100 and it works. switch must be using the semantics of === which means 'type and value are equal' vs ==, which will try to make the types similar and then pare.

EDIT -- here is a screenshot showing it working

You're paring the number 100 to the string "100", that isn't the same. Try this:

var x = 18;
var y = 82;

var result = x + y;

switch(result) {
case 200:
document.write("200!");
break;
case 500:
document.write("500!");
break;
case 100:
document.write("100! :)");
break;
default:
document.write("Something's not right..");
}

You are using strings in your case statements. Take the quotes (") out and you should be fine.

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