For Loop

Sometimes when programming, it's necessary to perform the same or almost the same operation a couple of times.

To prevent writing the same thing over and over again, we can use Loops.

The for loop has the following syntax:

for (initialization; condition; update) {
	code
}

The initialization, condition and update determine what is the start value and what is the end value.

For example, loop from 0 to 5 (not including):

for (int i = 0; i < 5; i++) {
	Console.WriteLine(i);
}

Breaking down the for loop:

1. Initialization: int i = 0
   • This runs once at the very beginning
   • Creates a variable i and sets its starting value to 0
2. Condition: i < 5
   • This is checked before each iteration
   • The loop continues as long as this condition is true
   • When i becomes 5, the condition becomes false and the loop stops
3. Update: i++
   • This runs after each iteration
   • Increases the value of i by 1 each time
   • i++ is shorthand for i = i + 1

for (int i = 0;  i < 5;  i++) {
     │           │        │
     │           │        └── Update
     │           └─────────── Condition
     └─────────────────────── Initialization

It will execute the print statement 5 times:

0
1
2
3
4

Loops have many use cases. For example, let's sum all the numbers from 1 to 100:

int sumNumbers = 0;
for (int i = 1; i <= 100; i++) {
	sumNumbers += i;
}
Console.WriteLine(sumNumbers);

This will first loop through all numbers between 1 and 100 (including 100 because of <= sign) and sum all of them, then it will print the sumNumbers variable