Learn to Program with C_ Learn to Program using the Popular C Programming Language ( PDFDrive )

Chapter 7 ■ Functions
We say that we call (or invoke) the function with the argument. (In this book, we use the term
‘parameter’ when referring to the definition of the function and the term ‘argument’ when the
function is called. Others use the terms interchangeably.) The “call” is executed as follows:
• The value of the argument is determined. In this case, it is just the constant 3
but, in general, it could be an expression.
• The value is copied to a temporary memory location. This location is passed
to the function where it is labeled with the name of the parameter, n. In
effect, the parameter variable n is set to the value of the argument. We can
picture this as follows:
n 3
• The body of the function is executed. In this case, since n is 3, the for loop
becomes
for (int h = 1; h <= 3; h++)
and it prints \n three times.
• When the function is finished, the location containing the argument
is discarded and control returns to main to the statement following
skipLines(3).
Note that we can get skipLines to print a different number of blank lines by supplying a
different argument when we call it.
When the value of an argument is passed to a function, we say the argument is passed “by
value.” In C, arguments are passed “by value.”
7.3 A Program with a Function
We write Program P7.1 to show how skipLines fits into a complete program.
Program P7.1
#include <stdio.h>
int main() {
void skipLines(int);
printf("Sing a song of sixpence\n");
skipLines(2);
printf("A pocket full of rye\n");
} //end main
void skipLines(int n) {
for (int h = 1; h <= n; h++)
printf("\n");
} //end skipLines
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