有人能告诉我这个if语句是如何工作的吗？

本文介绍了有人能告诉我这个if语句是如何工作的吗？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

if（src.mCells [i] [j]）mCells [i] [j] = src.mCells [i] [j] - > clone（）; else mCells [我] [j] .reset（）; 我的尝试： if（src.mCells [i] [j]）mCells [i] [j] = src.mCells [i] [j] - > clone（）; else mCells [i] [j] .reset（）;

if (src.mCells [i] [j]) mCells [i] [j] = src.mCells [i] [j] ->clone(); else mCells [i] [j].reset(); What I have tried: if (src.mCells [i] [j]) mCells [i] [j] = src.mCells [i] [j] ->clone(); else mCells [i] [j].reset();

推荐答案

C（C ++所基于的）没有布尔值的概念：相反，任何非零值被认为是真，只有零值被认为是假。 所以你的如果是只是简短的形式 C (on which C++ is based) did not have a concept of boolean values: instead, any non-zero value is considered "true" and only zero values are considered "false". So your if is just a short form of if (src.mCells [i] [j] != 0) ...

这是错误代码的一个很好的例子。 ;-) 我会写它（没有评论） it is a good example for bad code. ;-) I would write it (without the comments) if(src.mCells[i][j] != 0)//sanity check { mCells[i][j] = src.mCells[i][j]->clone(); //make copy } else { mCells[i][j].reset();//defaulting }

最好在if / else代码中使用大括号来提高可读性和维护性。

It is best to use braces in if/else code for readability and maintenance.