空声明

¥Syntax

;

¥Description

空语句是一个分号 (;)，表示不会执行任何语句，即使 JavaScript 语法需要一个语句。

¥The empty statement is a semicolon (;) indicating that no statement will be executed, even if JavaScript syntax requires one.

相反的行为，即你想要多个语句，但 JavaScript 只允许单个语句，可以使用 块语句 来实现，它将多个语句组合成一个语句。

¥The opposite behavior, where you want multiple statements, but JavaScript only allows a single one, is possible using a block statement, which combines several statements into a single one.

¥Examples

¥Empty loop body

空语句有时与循环语句一起使用。请参阅以下带有空循环体的示例：

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

const arr = [1, 2, 3];

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

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

¥Unintentional usage

对有意使用空语句进行注释是个好主意，因为它与普通分号的区别并不明显。

¥It is a good idea to comment intentional use of the empty statement, as it is not really obvious to distinguish from a normal semicolon.

在下面的示例中，这种用法可能不是有意的：

¥In the following example, the usage is probably not intentional:

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

¥See also

• 块语句