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

Sintaxe

;

Descrição

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.

Exemplos

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 gets always 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();

Especificações

Especificações Status Comentário
ECMAScript 2016 Draft (7th Edition, ECMA-262)
The definition of 'Empty statement' in that specification.
Draft  
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 Definição inicial.

Browsers compatíveis

Recurso Chrome Firefox (Gecko) Internet Explorer Opera Safari
Suporte Básico (Yes) (Yes) (Yes) (Yes) (Yes)
Recurso Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Suporte Básico (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)

Veja também

Etiquetas do documento e colaboradores

 Colaboradores desta página: joao_sanches
 Última atualização por: joao_sanches,