Question

我正在使用C ++，并且我有一定的增量和减量，但我有一个等式，我必须递减theChar等式，或者int var递减-2，我不知道它的代码。

Answer 1

请更好地制定您的问题。

是什么意思？

我有一个等式，我必须减少“theChar”等式，或者带有“int var”by -2
的那个

你的意思是：

char x = 'a';
x = x + 3; //now x is 'd'
int var = 10; 
var -= 2; //equal to var = var -2;

Answer 2

方程式不是方程式数学意义上的方程式。

=符号告诉计算机将右侧的内容存储在左侧的变量中。

int a;
a = 5;

这会将5存储到a一次。

int a, b;
a = 5;
b = a;
a = 6;

b仍然是5，因为它存储时会从a复制。 a更改时b未重新计算，但保持不变。

int a;
a = 5;
a = a - 2;

a现在正在减少2，因为a设置为5，当计算右侧（a - 2）时，它被计算为3 a。完成后，它会被写入左侧，恰好是a，所以此时3会被char c = 'B'; c = c - 1;覆盖;

'A'在此代码末尾的值为'B'。幕后有一些魔术在继续。字符也是数字。那么当我将66存储到计算机实际存储的变量66中时会发生什么。您可以阅读here。当我递减1时，该值从65递减到65。数字'A'的字符恰好是#include <iostream> using namespace std; int main() { int a, b; char c; //cout is like a friend that you give something to put on the console // << means give this to cout cout << "Hello World!" << endl; //endl is a new line character cout << endl << "Setting a, b" << endl; a = 5; b = a; cout << "Value of a is " << a << ". " << "Value of b is " << b << "." << endl; cout << endl << "Changing a" << endl; a = 3; cout << "Value of a is " << a << ". " << "Value of b is " << b << "." << endl; cout << endl << "Adding to a" << endl; a = a + 3; cout << "Value of a is " << a << ". " << "Value of b is " << b << "." << endl; cout << endl << "Playing around with characters" << endl; c = 'B'; cout << "Character c is " << c << ". " << "Number stored for c is actually " << (int)c << "." << endl; c = c + 1; cout << "Character c is " << c << ". " << "Number stored for c is actually " << (int)c << "." << endl; c = 70; cout << "Character c is " << c << ". " << "Number stored for c is actually " << (int)c << "." << endl; }。

我在评论中读到，您无法将其全部放入程序中。我继续为你写了一段代码片段。

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简单的初学者C ++，递增和递减问题

2 个答案: