Discuss a C language problem

qinqingshu

What compiler is used?

coolerpker

This is related to the compiler

xufeng001

It should be the language standard. Among the language option keywords in the assembly, the C and STDCALL keywords are pushed in the process parameters in reverse order, and the PASCAL keyword is pushed in the parameters in the forward order.

qqzhuping10

Give you a suggestion,
If not sure. Just use i. And then write a line ++

a = i;
i ++;

I don't really know how big the gap is after compilation, especially the compiler optimization is still very powerful.
Even if there is a gap, it is not very special and has no effect. Wait until the program is fine and optimize it.

桃之妖妖

Everyone upstairs said that.
This is compiler related. It is recommended not to use this when programming. I can't figure out what went wrong.

whl8125

My understanding, printf shows the value of the variable after executing this statement, so it is easy to understand
printf ("% d,% d", i, i ++); // This situation is shown as: 3,2-at the beginning i = 2, after executing this statement, i = 3 because of i ++, but The value of i ++ expression is still 2

printf ("% d,% d", i, ++ i); // This case is displayed as: 3,3-After executing this statement i = 3, (++ i) = 3
The explanation of the last two sentences is similar to the previous two sentences, and the result is no problem.
printf ("% d,% d", i ++, i); // This case is displayed as: 2,3
printf ("% d,% d", ++ i, i); // This case is displayed as: 3,3

mars1004

Someone has said upstairs that when calling functions, the C language standard does not specify the order of parameter calculation. Please do not write such code. Different compilers will behave differently.

xkn009

The compiler scans from right to left, setting i = 5
printf ("% d,% d", i, i ++); // 6,5
printf ("% d,% d", i, ++ i); // 6,6,
printf ("% d,% d", i ++, i); // 5,5
printf ("% d,% d", ++ i, i); // 6,5

123ffff

The key is to execute from right to left
There is auto-increment before and after use.

leintxw

If you don't consider the other behaviors of the compiler, only consider pushing the stack from right to left. . .

printf ("% d,% d", i, i ++); // 3,2
printf ("% d,% d", i, ++ i); // 3,3,
printf ("% d,% d", i ++, i); // 2,2
printf ("% d,% d", ++ i, i); // 3,2

But the actual situation will vary depending on the behavior of the compiler, so this form is uncertain.

Remember this in effect c ++. . .