Why loops are used?

Answer 1

Loops are used in C to speed up algorithms that do a process repeatedly with the same or very similar values. For example, if you have to write a program to add together all of the number 1 to 10 and print out the value you get you could do it 2 ways:

1. Without a loop:

int a = 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10;

printf("%d", a);

2. With a loop:

int a = 0;

for(int i = 1; i <= 10; i++){

a += i;

}

printf("%d", a);

As you can see, solution 2 took about the same amount of time to code as solution 1 BUT when you get into more complex things, or just things that involve more values, loops come in handy. For example, say you want to add up all of the numbers from 1 to 100 or 1 to 1000, it would take much longer to write that out as hard code rather than just to use a loop.