---
title: Javascript Switch
description: "> The `switch` statement is used to perform different actions based on different conditions. > > > > `switch` мэдэгдэл нь янз бүрийн нөхцөлд үндэслэн янз бүрийн үйлдлийг хийхэд хэрэглэгддэг. --- ## The JavaScript Switch Statement Use the `switch` statement to select one of…"
url: "https://apprentice.mn/docs/javascript-switch/"
updated: "2021-07-28"
category: Javascript
---

# Javascript Switch

> The `switch` statement is used to perform different actions based on different conditions.
>
>
>
> `switch` мэдэгдэл нь янз бүрийн нөхцөлд үндэслэн янз бүрийн үйлдлийг хийхэд хэрэглэгддэг.

---

## The JavaScript Switch Statement

Use the `switch` statement to select one of many code blocks to be executed.

`switch` -ийг ашиглан олон кодын блокуудын аль нэгийг сонгоно уу.

### Syntax Синтакс

  switch(*expression*) {
  case *x*:
*    // code block*    break;
  case *y*:
*    // code block*    break;
  default:
    // *code block*
}

This is how it works:

Энэ нь хэрхэн ажиллах вэ:

- The switch expression is evaluated once.
  Шилжүүлэгчийн илэрхийлэлийг нэг удаа үнэлнэ.
- The value of the expression is compared with the values of each case.
  Илэрхийллийн утгыг тохиолдол бүрийн утгатай харьцуулна.
- If there is a match, the associated block of code is executed.
  Хэрэв таарч байвал холбогдох кодын блокыг гүйцэтгэнэ.
- If there is no match, the default code block is executed.
  Хэрэв тохирох зүйл байхгүй бол анхдагч кодын блокыг гүйцэтгэнэ.

### Example Жишээ

The `getDay()` method returns the weekday as a number between 0 and 6.

`getDay()` арга нь ажлын өдрийг 0-6 хоорондох тоогоор буцаана.

(Sunday=0, Monday=1, Tuesday=2 ..)

This example uses the weekday number to calculate the weekday name:

Энэ жишээнд ажлын өдрийн нэрийг тооцоолохдоо ажлын өдрийн дугаарыг ашиглана.

       `switch (new Date().getDay()) {
  case 0:
    day = "Sunday";
    break;
  case 1:
    day = "Monday";
    break;
  case 2:
     day = "Tuesday";
    break;
  case 3:
    day = "Wednesday";
    break;
  case 4:
    day = "Thursday";
    break;
  case 5:
    day = "Friday";
    break;
  case 6:
    day = "Saturday";
}`

The result of day will be:

     `Thursday`

## The break Keyword

When JavaScript reaches a `break` keyword, it breaks out of the switch block.

This will stop the execution inside the switch block.

It is not necessary to break the last case in a switch block. The block breaks (ends) there anyway.

**Note: **If you omit the break statement, the next case will be executed even if the evaluation does not match the case.

---

## The default Keyword

The `default` keyword specifies the code to run if there is no case match:

### Example

The `getDay()` method returns the weekday as a number between 0 and 6.

If today is neither Saturday (6) nor Sunday (0), write a default message:

      `switch (new Date().getDay()) {
  case 6:
    text = "Today is Saturday";
    break;
  case 0:
    text = "Today is Sunday";
    break;
  default:
    text = "Looking forward to the Weekend";
}`

The result of text will be:

     `Looking forward to the Weekend`

The `default` case does not have to be the last case in a switch block:

### Example

      `switch (new Date().getDay()) {
  default:
    text = "Looking forward to the Weekend";
    break;
  case 6:
    text = "Today is Saturday";
    break;
  case 0:
    text = "Today is Sunday";
}`

If `default` is not the last case in the switch block, remember to end the default case with a break.

---

## Common Code Blocks

Sometimes you will want different switch cases to use the same code.

In this example case 4 and 5 share the same code block, and 0 and 6 share another code block:

### Example

      `switch (new Date().getDay()) {
  case 4:
  case 5:
    text = "Soon it is Weekend";
    break;
  case 0:
  case 6:
    text = "It is Weekend";
    break;
  default:
    text = "Looking forward to the Weekend";
}`

> ## Switching Details
>
>
>
> If multiple cases matches a case value, the **first** case is selected.
>
>
>
> If no matching cases are found, the program continues to the **default** label.
>
>
>
> If no default label is found, the program continues to the statement(s) **after the switch**.

---

## Strict Comparison

Switch cases use **strict** comparison (===).

The values must be of the same type to match.

A strict comparison can only be true if the operands are of the same type.

In this example there will be no match for x:

### Example

      `var x = "0";
switch (x) {
  case 0:
    text = "Off";
    break;
  case 1:
    text = "On";
    break;
  default:
    text = "No value found";
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