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C program Output


 
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# 1  
C program Output

The output I got for this pgm is "4 4 4 4".
Can any one help me to understand how I got this output.

Also please suggest me some links to learn about argumnets evaluation in C.

# include <stdio.h>

void func(int a, int b, int c, int d)
{
printf("%d %d %d %d", a, b, c, d);
}

int main()
{
int x = 0;
func(++x, ++x, ++x, ++x);
return 0;
}
# 2  
The output should have been like

Output:

Code:
4 3 2 1

The reason is the value is evaluated from the right to left in the argument list passed to printf so each and every time ++x is encountered the value of x is incremented.
# 3  
Quote:
Originally Posted by lorcan
The output should have been like
Or rather " 'may' have been like".

The ++ operator means increment before use it's value.

So technically having ++x,++x,++x,++x

can be interpreted as increment four times before you use it's value.

This one area where you have to be careful, especially with macro expansions.

Different compilers, different architectures and different optimisations can give you different results.
# 4  
Quote:
Originally Posted by lorcan
The reason is the value is evaluated from the right to left in the argument list passed to printf so each and every time ++x is encountered the value of x is incremented.
I would have thought that the entire arguments list is first evaluated and then sent to printf (which explains the output).

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