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← Introduction to JavaScript
○What is JavaScript?○Your First JavaScript Code○Data Types○Type Checking
○Declaring Variables○let and const in Practice○Operators○Type Conversion
○Conditionals○Switch Statement●For Loops○While Loop○Break and Continue
○Defining Functions○Arrow Functions○Scope○Closures○Project - Calculator○Function Expressions
○Arrays○Array Mutation Methods○Array Search and Slice○Array Iteration Methods○Multidimensional Arrays○Destructuring○Array Reverse and Sort○Array Fill○Array Find and Includes○Array Flat and FlatMap○Array Reduce, Some, and Every
○Objects○Object Methods and Destructuring○JSON○Math and Date○Date Basics
○02 Template Literals○String Methods○Regular Expressions
○Higher-Order Functions○Callbacks○map, filter, and reduce○Recursion○Project - Data Transform Pipeline
○OOP Introduction○Classes○Inheritance○Encapsulation
○Asynchronous JavaScript○Promises and Async Await○Async API Simulation

For Loops

Loops let you repeat a block of code. JavaScript offers several loop styles.

Traditional for loop

javascript
for (let i = 0; i < 5; i++) {
    console.log(i); // 0 1 2 3 4
}

Iterating an array:

javascript
const fruits = ["apple", "banana", "cherry"];
for (let i = 0; i < fruits.length; i++) {
    console.log(fruits[i]);
}

for...of — iterate values

Cleaner syntax when you only need the value, not the index:

javascript
for (const fruit of fruits) {
    console.log(fruit);
}

for...in — iterate object keys

javascript
const person = { name: "Alice", age: 30 };
for (const key in person) {
    console.log(key, person[key]); // name Alice / age 30
}

Your Task

  1. Write a function sumArray(numbers) that returns the sum of all numbers in the array using a for loop.
  2. Write a function reverseArray(arr) that returns a new array with the elements in reverse order.
  3. Call sumArray([1, 2, 3, 4, 5]) and display in #output as "Sum: 15".
Hint 1
1 / 3
HINT 1

A standard for loop: for (let i = 0; i < arr.length; i++).

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