The break statement terminates the current loop, switch, or label statement and transfers program control to the statement following the terminated statement.
break [label];
label
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.
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; }
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 }
The following code also uses break
statements with labeled blocks but generates a Syntax Error 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'); }
Created by Mozilla Contributors, license: CC-BY-SA 2.5