#include <stdio.h>
int main(void)
{
int i = 0;
i = i++ + ++i;
printf("%d\n", i); // 3
i = 1;
i = (i++);
printf("%d\n", i); // 2 Should be 1, no ?
volatile int u = 0;
u = u++ + ++u;
printf("%d\n", u); // 1
u = 1;
u = (u++);
printf("%d\n", u); // 2 Should also be one, no ?
register int v = 0;
v = v++ + ++v;
printf("%d\n", v); // 3 (Should be the …Run Code Online (Sandbox Code Playgroud) c increment operator-precedence undefined-behavior sequence-points
逗号运算符如何在C++中工作?
例如,如果我这样做:
a = b, c;
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最终是否等于b或c?
(是的,我知道这很容易测试 - 只是在这里记录,以便有人快速找到答案.)
更新: 此问题在使用逗号运算符时暴露了细微差别.只是记录下来:
a = b, c; // a is set to the value of b!
a = (b, c); // a is set to the value of c!
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这个问题实际上是受到代码中的拼写错误的启发.打算做什么
a = b;
c = d;
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转换成
a = b, // <- Note comma typo!
c = d;
Run Code Online (Sandbox Code Playgroud) 你以前试过这个吗?
static void Main(string[] args)
{
int x = 10;
x = x++;
Console.WriteLine(x);
}
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产量:10.
但对于
static void Main(string[] args)
{
int x = 10;
x++;
Console.WriteLine(x);
}
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产量:11.
谁能解释为什么这个?