Loops

A loop makes the computer repeat the same lines of code multiple times.

The 3 sss-es

In theory. every loop should have (whether explicit or behind the scenes) the following 3 components:

• The start = initial state/conditions when first entering the loop
• The stop = the condition to exit the loop
• The step = an instruction that (ideally) moves the loop closer to it's stop In practice, you can write loops that are missing some components, resulting in either a loop that is not working, or a loop that is not stopping. There's 3 types of loops that you can write:

The while loop

A while is a loop is defined with a boolean. When the boolean is true the loop is executed, when the boolean is false the loop is not executed. But that is not very helpful, which is why a while loop 99% of the time is defined with a condition (the result of which is a boolean). It is generally used when the number of steps is unknown.

bool condition;
while(condition)
{
	//do stuff
}

The do while loop

It is identical to the while loop, except the condition is written at the end. This makes it so the loop is executed at least once.

bool condition;
do
{
	//do stuff
}
while(condition);

The for loop

A for loop is defined with a starting state, an end condition, and a step. It is generally used when the number of repeats is known beforehand.

//note the (start;stop;step) format
for(int i = 1; i <= 10; i++)
{
	//do stuff
}

It is equivalent to the following while loop

int i = 1;
while(i <= 10)
{
	//do stuff
	i++;
}

The foreach loop

Foreach is a loop that iterates over collections.

List<int> someNumbers = [1, 3, 5, 7, 9];
foreach(int number in someNumbers)
{
	//do something with the number
}

It is equivalent to the following for loop:

List<int> someNumbers = [1, 3, 5, 7, 9];
for(int i = 0; i < someNumbers.Length; i++)
{
	int number = someNumbers[i];
	//do something with the number
}