Sub-programs definition & call

6. As a final improvement, the variable x can be transformed into a parameter

int abs(int x) {
   if (x<0) { x=-x; } else {}
   return x;
}

int main() {
   printf("%i", abs(-12) );
   printf("%i", abs( 24) );
}

Comments:
a. The parameters and returned value have a specific representation.
b. The printf is a sub-program having two parameter with a format, eg. "%i" for an integer, and a value.

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