``````// A series of demos on looping in C

// Marc Chee, February 2020

#include <stdio.h>

int main(void) {
// *****************************************************
// This first loop is a basic loop with a counter

// an integer outside the loop
int counter = 0;

while (counter < 10) { // this code has run counter number of times
printf("The first loop has completed %d times.\n", counter);
counter = counter + 1;
}
// When counter hits 10 and the loop's test fails
// the program will exit the loop

// *****************************************************
// This second loop shows the risk of asking the wrong
// question in the loop!
// This program will never end if this loop runs!
//while (1 < 2) {
// Never going to give you up
// Never going to let you down . . .
//}

// *****************************************************
// This loop will end only when a certain condition is
// met. When it detects that the input number is odd

// an integer outside the loop
int endLoop = 0;

// The loop will exit if it reads an odd number
while (endLoop == 0) {
int inputNumber;
printf("Please type in a number: ");
scanf("%d", &inputNumber);
if (inputNumber % 2 == 0) {
printf("Number is even.\n");
} else {
printf("Number is odd.\n");
endLoop = 1;
}
}

// *****************************************************
// A loop within a loop. These should draw a grid of
// stars

int y = 0;
// loop through and print multiple rows
while (y < 10) { // we have printed y rows
// print a single row
int x = 0;
while (x < 10) { // we have printed x stars in this row
printf("*");
x = x + 1;
}
// the row is finished, start the next line
printf("\n");
y = y + 1;
}

return 0;
}
``````

Resource created Monday 24 February 2020, 06:59:57 PM.

file: loopDemo.c