Switch Statement for Multiple Cases in JavaScript

Switch statement for multiple cases in JavaScript

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');
}

Test for multiple cases in a switch, like an OR (||)

You can use fall-through:

switch (pageid)
{
    case "listing-page":
    case "home-page":
        alert("hello");
        break;
    case "details-page":
        alert("goodbye");
        break;
}

Why is my switch statement running multiple cases?

It's because you don't have a break statement. Without it, the code will "fall through".

var x = 10;switch (x) {  case 10:    console.log('With break');    break;      case 20:    console.log('I never run');    break;}
console.log('-------');
switch (x) {  case 10:    console.log('Without');  case 20:    console.log('a break');  case 30:    console.log('it just');  case 40:    console.log('keeps going');}

JavaScript, Typescript switch statement: way to run same code for two cases?

Just put them right after each other without a break

switch (myVar) {
  case 68:
  case 40:
    // Do stuff
  break;

  case 30:
    // Do stuff
  break;
}

Javascript Switch Statement multiple cases return the values

You could take an object with the wanted values and get an array of strings.

var values = { Beef: "Cows", Pork: "Pigs", Sheep: "Sheep", Goat: "Goats", Lamb: "Lambs", Rabbit: "Rabbit", OtherMeat: "Other", Chicken: "Chicken", Turkey: "Turkey", Duck: "Duck", Goose: "Geese", Pheasant: "Pheasants", Quail: "Quail", OtherPoultry: "Other Poultry" };
    result = Object
        .keys(popup.properties)
        .filter(k => popup.properties[k] === 'Yes')
        .map(k => values[k]);

Javascript Switch: can you use the same case multiple times?

No, it doesn't work. It only seems to work because you are missing a break after the first case. Without that break, if the second case was called anything, it would be executed.

For instance, if you called the second case case 'foo': it would still set height/width properties. The height and width are applied because of the missing break in the previous case statement.

Credit @machinegost and @jorg for the following additional sources, respectively:

• https://help.semmle.com/wiki/display/JS/Duplicate+switch+case
• ECMA 2015 Spec: Switch Statement Static Semantics (Early Errors)

Switch always hits Default Case JS

Instead of using switch you could build a little dictionary object, and then reference the values using the key. It's a little less unwieldy.

const obj = {
  DAR: 'Delivered and Recieved',
  DCR: 'Delivery Completion Rate'
};

function setTitle(data) {
  console.log(data);
}

function handleOption(option) {
  setTitle(obj[option]);
}

handleOption('DAR');
handleOption('DCR');

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