Question

在我的c ++书中，有这个循环：

AnswerSelectedId = CorrectAnswerId

这似乎永远循环。我无法阻止这个循环。这有什么用途？

Answer 1

operator>>将返回流（cin），该流本身可以转换为bool，表示流是否仍然有效。这将循环，直到导致cin的读取失败（文件结束，字母而不是数字等）。

Answer 2

这类似于：

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在哪里连续读取数字并打印出来。输入一个非数字会导致输入流失败，因此cin.good（）变为false。（流不再好）

为什么cin被用作循环条件？

2 个答案: