functions in C

Exit status

• When a program ends, a special exit code is provided to the computer.
  • main function returns an int
• technically programs can also secretly return numbers to signal methodically whether the program was successful or not
  • status code 0 →program exits without error
  • status code 1 →when an error occurs that results in the program ending
• echo $?
  • shows the exit status of the most recent command

Declaration vs Definition

• function declaration
  • return type, name, arguments.;
• function definition
  • actual implementation of the function

Order of functions & prototypes

void meow(void); // you need to add the prototype like this
 
int main(void) {
	for (int i = 0; i < 3; i++) {
		meow();
	}
}
 
void meow(void) {
	print("meow");
}

• C can only read from top to bottom
• So you need to add the prototype of your function on the top
  • 1st line of the function
  • “hey, there is a function called meow and it will eventually exist”