Lesson 11

Loops

Loops allow you to execute a block of code multiple times until a certain condition is met.

for Loop
while Loop
do...while Loop
break & continue
Nested Loops

forfor Loop

Use when you know how many times to iterate.

for (let i = 0; i < n; i++) {  // code}

Best for: Count based loops

whilewhile Loop

Use when the number of iterations is unknown.

while (condition) {  // code}

Best for: Condition based loops

dodo...while Loop

Similar to while, but executes at least once.

do {  // code} while (condition);

Best for: Menu, validations

JavaScript

1for (let i = 1; i <= 5; i++) {
2  console.log("Iteration:", i);
3}
4
5let sum = 0;
6for (let i = 1; i <= 5; i++) {
7  sum += i;
8}
9console.log("Sum:", sum);

Output

Your output will appear here...

for (init; condition; update) {  // code}

```
while (condition) {  // code}
```
```
do {  // code} while (condition);
```

Always ensure your loop condition will eventually become false, otherwise you may create an infinite loop!

Use a for loop when you know the count, a while loop when you don’t, and do...while when the code must run at least once. break exits the loop early and continue skips to the next iteration.