Is it possible to use .contains() in a switch statement?

Question

This is just a simple example of what I'm trying to do:

switch (window.location.href.contains('')) {     case "google":         searchWithGoogle();         break;     case "yahoo":         searchWithYahoo();         break;     default:         console.log("no search engine found"); } 

If it's not possible/feasible what would be a better alternative?

Solution:

After reading some of the responses I found the following to be a simple solution.

function winLocation(term) {     return window.location.href.contains(term); } switch (true) {     case winLocation("google"):         searchWithGoogle();         break;     case winLocation("yahoo"):         searchWithYahoo();         break;     default:         console.log("no search engine found"); } 

Answer 1

"Yes", but it won't do what you expect.

The expression used for the switch is evaluated once - in this case contains evaluates to true/false as the result (e.g. switch(true) or switch(false)) , not a string that can be matched in a case.

As such, the above approach won't work. Unless this pattern is much larger/extensible, just use simple if/else-if statements.

var loc = .. if (loc.contains("google")) {   .. } else if (loc.contains("yahoo")) {   .. } else {   .. } 

However, consider if there was a classify function that returned "google" or "yahoo", etc, perhaps using conditionals as above. Then it could be used as so, but is likely overkill in this case.

switch (classify(loc)) {    case "google": ..    case "yahoo": ..    .. } 

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While the above discusses such in JavaScript, Ruby and Scala (and likely others) provide mechanisms to handle some more "advanced switch" usage.

Answer 2

An alternative implementation might be this. Not much in it but reads better than switch(true)...

const href = window.location.href; const findTerm = (term) => {   if (href.includes(term)){     return href;   } };  switch (href) {   case findTerm('google'):       searchWithGoogle();       break;   case findTerm('yahoo'):       searchWithYahoo();       break;   default:       console.log('No search engine found'); };