Switch statement multiple cases in JavaScript

Switch statement multiple cases in JavaScript

I need multiple cases in switch statement in JavaScript, Something like:
switch (varName)
{
case “afshin”, “saeed”, “larry”:
alert(‘Hey’);
break;

default:
alert(‘Default case’);
break;
}

How can I do that? If there’s no way to do something like that in JavaScript, I want to know an alternative solution that also follows DRY concept.

Solutions/Answers:

Solution 1:

Use the fall-through feature of the switch statement. A matched case will run until a break (or the end of the switch statement) is found, so you could write it like:

switch (varName)
{
   case "afshin":
   case "saeed":
   case "larry": 
       alert('Hey');
       break;

   default: 
       alert('Default case');
}

Solution 2:

This works in regular JavaScript

function theTest(val) {
  var answer = "";
  switch( val ) {
    case 1: case 2: case 3:
      answer = "Low";
      break;
    case 4: case 5: case 6:
      answer = "Mid";
      break;
    case 7: case 8: case 9:
      answer = "High";
      break;
    default:
      answer = "Massive or Tiny?";
  } 
  return answer;  
}

theTest(9);

Cheers.

Solution 3:

Here’s different approach avoiding the switch statement altogether:

var cases = {
  afshin: function() { alert('hey'); },
  _default: function() { alert('default'); }
};
cases.larry = cases.saeed = cases.afshin;

cases[ varName ] ? cases[ varName ]() : cases._default();

Solution 4:

In Js for assign multiple cases in switch We have to define different case without break like given below:

   <script>
      function checkHere(varName){
        switch (varName)
           {
           case "saeed":
           case "larry":
           case "afshin":
                alert('Hey');
                break;
          case "ss":
               alert('ss');
               break;
         default:
               alert('Default case');
               break;
       }
      }
     </script>

Please see example click on link

Solution 5:

If you’re using ES6, you can do this:

if (['afshin', 'saeed', 'larry'].includes(varName)) {
   alert('Hey');
} else {
   alert('Default case');
}

Or for earlier versions of JavaScript, you can do this:

if (['afshin', 'saeed', 'larry'].indexOf(varName) !== -1) {
   alert('Hey');
} else {
   alert('Default case');
}

Note that this won’t work in older IE browsers, but you could patch things up fairly easily. See the question determine if string is in list in javascript for more information.

Solution 6:

Adding and clarifying Stefano’s answer, you can use expressions to dinamically set the values for the conditions in switch, e.g.:

var i = 3
switch (i) {
    case ((i>=0 && i<=5)?i:-1): console.log('0-5'); break;
    case 6: console.log('6');
}

So in your problem, you could do something like:

var varName = "afshin"
switch (varName) {
    case (["afshin", "saeed", "larry"].indexOf(varName)+1 && varName):
      console.log("hey");
      break;

    default:
      console.log('Default case');
}

although not being so much DRY..