How do I explain the output of this simple C code?

Question

#include
int main()
{
int i=10;
printf(\"%d\",printf(\"%d\",i));
return(0);
}

Output in Turbo C

102

Answer 1

printf() is a C function. It returns an int value equal to the number of bytes it prints.

In your case, the INNER printf printed "10", so it wrote 2 bytes and will return 2.

The OUTER printf will therefore print "2".

Final result: "102" ("10" of the INNER followed by "2" of the OUTER).