Question

I am not able to understand the output of the following C code :

#include<stdio.h>
main()
{
   char * something = "something";
   printf("%c", *something++);  // s
   printf("%c", *something);    // o
   printf("%c", *++something);  // m
   printf("%c", *something++);  // m
}

Please help 🙂

Answer 1

// main entrypoint
int main(int argc, char *argv[])
{
    char * something = "something";

    // increment the value of something one type-width (char), then
    //  return the previous value it pointed to, to be used as the 
    //  input for printf.
    // result: print 's', something now points to 'o'.
    printf("%c", *something++);

    // print the characer at the address contained in pointer something
    // result: print 'o'
    printf("%c", *something);

    // increment the address value in pointer something by one type-width
    //  the type is char, so increase the address value by one byte. then
    //  print the character at the resulting address in pointer something.
    // result: something now points at 'm', print 'm'
    printf("%c", *++something);

    // increment the value of something one type-width (char), then
    //  return the previous value it pointed to, to be used as the 
    //  input for printf.
    // result: print 's', something now points to 'o'.
    printf("%c", *something++);
}

Result:

somm