Önkénteseink még nem fordították le ezt a cikket magyar nyelvre. Csatlakozzon, és segítsen a munka befejezésében!
Elolvashatja a cikket English (US) nyelven is.

An empty statement is used to provide no statement, although the JavaScript syntax would expect one.

Syntax

;

Description

The empty statement is a semicolon (;) indicating that no statement will be executed, even if JavaScript syntax requires one. The opposite behavior, where you want multiple statements, but JavaScript only allows a single one, is possible using a block statement; it combines several statements into a single one.

Examples

The empty statement is sometimes used with loop statements. See the following example with an empty loop body:

var arr = [1, 2, 3];

// Assign all array values to 0
for (i = 0; i < arr.length; arr[i++] = 0) /* empty statement */ ;

console.log(arr)
// [0, 0, 0]

Note: It is a good idea to comment the intentional use of the empty statement, as it is not really obvious to distinguish between a normal semicolon. In the following example the usage is probably not intentional:

if (condition);       // Caution, this "if" does nothing!
   killTheUniverse()  // So this always gets executed!!!

Another Example: An if...else statement without curly braces ({}). If three is true, nothing will happen, four does not matter, and also the launchRocket() function in the else case will not be executed.

if (one)
  doOne();
else if (two)
  doTwo();
else if (three)
  ; // nothing here
else if (four)
  doFour();
else
  launchRocket();

Specifications

Specification Status Comment
ECMAScript Latest Draft (ECMA-262)
The definition of 'Empty statement' in that specification.
Living Standard  
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Empty statement' in that specification.
Standard  
ECMAScript 5.1 (ECMA-262)
The definition of 'Empty statement' in that specification.
Standard  
ECMAScript 3rd Edition (ECMA-262)
The definition of 'Empty statement' in that specification.
Standard  
ECMAScript 1st Edition (ECMA-262)
The definition of 'Empty statement' in that specification.
Standard Initial definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic Support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)
FeatureAndroidChrome for AndroidEdge mobileFirefox for AndroidIE mobileOpera AndroidiOS Safari
Basic Support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)

See also

Dokumentum címkék és a közreműködők

Címkék: 
 Ezen oldal közreműködői: fscholz, jameshkramer, AviKav, Sebastianz, teoli, rogp
 Utoljára frissítve: fscholz,