# Ceaser Cipher

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## The for Loop

Whenever we need to perform a task or an action repeatedly, we use loops. The first type of loop we'll be looking at is the for loop.

For example if we need to add up all the number from 1 to 5 and log the result to the console, we can do it like this;

let sum = 1 + 2 + 3 + 4 + 5;
console.log(sum);
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

How about if need to add all the numbers from 1 to 100? We could do it by writing each number let sum = 1 + 2 + 3 + 4 ... etc. but this would take a long time.

This is where we can use a loop, a for loop to be exact:

let sum = 0; // we need to initialize sum.
for (let i = 1; i <= 100; i++) {
sum = sum + i;
}
console.log("the sum is: " + sum);
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Hint: You can write the expression sum = sum + i as sum += i

Notice the ++ operator? ++ means, add 1 to the value. so, i++ is the same as i = i + 1

Now, use a for loop to set sum equal to the sum of all multiples of 5 between 0 and 50.   