“IF”参数评价顺序？ [英] "IF" argument evaluation order?

问题描述

if(a && b)
{
  do something;
}

有可能从右到左计算参数）？

is there any possibility to evaluate arguments from right to left(b -> a)?

如果是，影响评估顺序？

if "yes", what influences the evaluation order?

推荐答案

评估顺序由标准指定，从左到右。最左侧的表达式将始终使用&& 子句求值。

The evaluation order is specified by the standard and is left-to-right. The left-most expression will always be evaluated first with the && clause.

如果你想要 b 首先进行评估：

If you want b to be evaluated first:

if(b && a)
{
  //do something
}

参数是方法，并且您希望对它们进行评估，而不考虑它们的结果：

If both arguments are methods and you want both of them to be evaluated regardless of their result:

bool rb = b();
bool ra = a();

if ( ra && rb )
{
  //do something
}

这篇关于“IF”参数评价顺序？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！