什么是X = X +之间的差值; VS X ++ ;? [英] What's the difference between X = X++; vs X++;?

问题描述

你有没有试过在这之前？

Have you ever tried this before?

static void Main(string[] args)
{
    int x = 10;
    x = x++;
    Console.WriteLine(x);
}

输出：10

但

static void Main(string[] args)
{
    int x = 10;
    x++;
    Console.WriteLine(x);
}

输出：11

谁能解释为什么？

推荐答案

X ++将增加值，但随后返回其旧值。

X++ will increment the value, but then return its old value.

因此​​，在这种情况下：

So in this case:

static void Main(string[] args)
{
    int x = 10;
    x = x++;
    Console.WriteLine(x);
}

您的X在11只一会儿，然后回来到10，因为10为（x ++）的返回值。

You have X at 11 just for a moment, then it gets back to 10 because 10 is the return value of (x++).

您可以改为做了同样的结果：

You could instead do this for the same result:

static int plusplus(ref int x)
{
  int xOld = x;
  x++;
  return xOld;
}

static void Main(string[] args)
{
    int x = 10;
    x = plusplus(x);
    Console.WriteLine(x);
}

另外，值得一提的是，你将有11您预期的结果，如果你会做：

It is also worth mentioning that you would have your expected result of 11 if you would have done:

static void Main(string[] args)
{
    int x = 10;
    x = ++x;
    Console.WriteLine(x);
}

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