c - 什么是 C 中的空语句？

Question

我想确切地知道，C语言中的null语句是什么？并解释它的典型用法。

我找到了以下代码段。

for (j=6; j>0; j++)
;

和

for (j=6; j>0; j++)

Answer 1

来自 msdn 页面:

The "null statement" is an expression statement with the expression missing. It is useful when the syntax of the language calls for a statement but no expression evaluation. It consists of a semicolon.

Null statements are commonly used as placeholders in iteration statements or as statements on which to place labels at the end of compound statements or functions.

了解更多:https://msdn.microsoft.com/en-us/library/1zea45ac.aspx

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And explain a typical use of it.

当你想查找字符串中某个字符第一次出现的索引时

int a[50] = "lord of the rings";
int i;

for(i = 0; a[i] != 't'; i++)
    ;//null statement
//as no operation is required