Web/JavaScript/Reference/statements/break-2

The break statement terminates the current loop, switch, or label statement and transfers program control to the statement following the terminated statement.

Syntax

break [label];

label Optional: Identifier associated with the label of the statement. If the statement is not a loop or switch, this is required.

Description

The break statement includes an optional label that allows the program to break out of a labeled statement. The break statement needs to be nested within the referenced label. The labeled statement can be any block statement; it does not have to be preceded by a loop statement.

A break statement, with or without a following label, cannot be used within the body of a function that is itself nested within the current loop, switch, or label statement that the break statement is intended to break out of.

Examples

break in while loop

The following function has a break statement that terminates the while loop when i is 3, and then returns the value 3 * x.

function testBreak(x) {
  var i = 0;

  while (i < 6) {
    if (i == 3) {
      break;
    }
    i += 1;
  }

  return i * x;
}

break in switch statements

The following code has a break statement that terminates the switch statement when a case is matched and the corresponding code has ran

const food = "sushi";

switch (food) {
  case "sushi":
    console.log("Sushi is originally from Japan.");
    break;
  case "pizza":
    console.log("Pizza is originally from Italy.");
    break;
  default:
    console.log("I have never heard of that dish.");
    break;
}

break in labeled blocks

The following code uses break statements with labeled blocks. A break statement must be nested within any label it references. Notice that inner_block is nested within outer_block.

outer_block: {
  inner_block: {
    console.log('1');
    break outer_block; // breaks out of both inner_block and outer_block
    console.log(':-('); // skipped
  }
  console.log('2'); // skipped
}

break in labeled blocks that throw

The following code also uses break statements with labeled blocks, but generates a SyntaxError because its break statement is within block_1 but references block_2. A break statement must always be nested within any label it references.

block_1: {
  console.log('1');
  break block_2; // SyntaxError: label not found
}

block_2: {
  console.log('2');
}

break within functions

SyntaxErrors are also generated in the following code examples which use break statements within functions that are nested within a loop, or labeled block that the break statements are intended to break out of.

function testBreak(x) {
  var i = 0;

  while (i < 6) {
    if (i == 3) {
      (function() {
        break;
      })();
    }
    i += 1;
  }

return i * x;
}

testBreak(1); // SyntaxError: Illegal break statement

block_1: {
  console.log('1');
  ( function() {
    break block_1; // SyntaxError: Undefined label 'block_1'
  })();
}

Specifications

Specification
ECMAScript (ECMA-262)The definition of 'Break statement' in that specification.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
`break`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 3	Opera Full support 4	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100

Legend

Full support: Full support