如何从另一个整数中减去两个整数之和然后递增呢？ [英] How do I subtract sum of two integers from another integer and then increment it?

问题描述

如何从z中减去x和y之和，然后在C ++中用单个语句递增它



我尝试过：

How to subtract sum of x and y from z and then increment it in a single statement in C++

What I have tried:

#include<iostream>
using namespace std;
int main()
{
	int x,y,z,p;
	x=5;
	y=6;
	z=20;
	p=(z-(x+y))++;
	cout<<"value of z="<<p;
}

显示分配的左操作数所需的错误值

it's showing error value required as left operand of assignment

推荐答案

引用：

我做过这个z = z-（x + y）;但是可以在同一行增加它吗?????

I've done this z=z-(x+y); but is it possible to increment it in the same line?????

否你需要所谓的左值 - 因为++运算符是一个快捷方式操作，基本上说复制此变量，将其递增1，然后使用您记住的值。你只能预先修改一个变量（或减少一个变量），而不是一个结果。



基本上，你试图通过自动增量运算符来创造：别。这种方式存在一些非常令人讨厌的问题。请参阅此处：为什么x = ++ x + x ++给我错误的答案？ [ ^ ]

No. You need what is called an lvalue - because the ++ operator is a "shortcut" operation which basically says "copy this variable, increment it by one, then use the value you remembered". You can only pre-or post fix increment (or decrement) a variable, not an result.

Basically, you are trying to get creative with the auto increment operators: don't. That way lies some really nasty problems. See here: Why does x = ++x + x++ give me the wrong answer?[^]

在作业的左侧需要一个变量。



首先在分隔语句中编写代码：

You need a single variable on the left side of an assignment.

Write the code first in separated statements:

z = z - (x + y); // Subtract sum of x and y from z; or z-= x + y
z = z + 1; // increment z; or z++

现在想想如何将它放入一行。

提示：从值中减去负数相当于添加数字的绝对值。

Think now how this can be put into one line.
Tip: Subtracting a negative number from a value is equivalent to adding the absolute value of the number.

这篇关于如何从另一个整数中减去两个整数之和然后递增呢？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！