c ++负平方根

本文介绍了c ++负平方根的处理方法，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

我的目标是如果平方根为负，则打印 *** 。但我不能想办法改变默认 nan 文本到 ***

for（int i = x1; i <= x2; i ++）{ double y = sqrt（pow * i-500）; if（y =？）{ outFile< ***;所以，我应该在if语句中写什么来使它成为可能？或者有另一种方法检查y是否为nan然后打印 *

解决方案

检查对平方根函数的负输入？

for（int i = x1; i < = x2; ++ i） { double x = pow（i，2）+ 3 * i-500; if（x< 0） { outFile< ***; } else { outFile< sqrt（x）; } }

My goal is to print *** if the square root is negative. But I can't think of a way to change default nan text to ***

for(int i=x1;i<=x2;i++){ double y = sqrt(pow(i,2)+3*i-500); if(y = ?){ outFile << "***"; }

So, what should I write in the if statement to make it possible? Or maybe there is another way to check if the y is nan then print *

解决方案

How about checking for a negative input to the square root function?

for (int i = x1; i <= x2; ++i) { double x = pow(i, 2) + 3*i - 500; if (x < 0) { outFile << "***"; } else { outFile << sqrt(x); } }