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

"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": ..   ..}

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

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');};