Course Content

JavaScript Data Structures

1. Introduction and Prerequisites

Introduction to JavaScript Data Structures Prerequisites for Learning JavaScript Data Structures What You'll Learn in This Course Tips for Success

2. Fundamentals of JavaScript Objects

Understanding Objects in JavaScript Creating Objects in JavaScript Working with Nested Object Properties Challenge: Create and Structure an Object Accessing Object Properties in JavaScript Challenge: Retrieve Object Property Values Managing Object Properties Challenge: Modify and Extend an Object Defining Object Methods Using Properties within Methods Challenge: Work with Object Methods Fundamentals of JavaScript Objects Sum-Up

3. Advanced Object Manipulation Techniques

Iterating Over Object Properties with the for...in Loop Challenge: Explore Object Properties with Iteration Using hasOwnProperty() to Check Object Properties Challenge: Object Property Iteration with hasOwnProperty()Cloning and Merging Objects with the Spread Operator Challenge: Combine Objects with the Spread Operator Destructuring Objects for Cleaner Code Challenge: Extract Data with Object Destructuring Advanced Object Manipulation Sum-Up

4. Mastering JavaScript Arrays

Understanding JavaScript Arrays Challenge: Access Array Elements Modifying Arrays and Accessing Elements Challenge: Modify Array Elements Iterating Over Arrays with the for Loop Challenge: Loop Through Arrays with for Using the for...of Loop for Array Iteration Challenge: Efficient Array Iteration with for...of Mastering JavaScript Arrays Sum-Up

5. Advanced Array Methods and Transformations

Transforming Arrays with the map() Method Challenge: Modify Array Elements Using map()Filtering Arrays with the filter() Method Challenge: Select Specific Data Using filter()Finding Elements in an Array with the find() Method Challenge: Search for Items Using find()Sorting Arrays with the sort() Method Challenge: Sort and Extract Data with sort()Advanced Array Methods and Transformations Sum-Up Course Summary

Challenge: Modify Array Elements

Task

The task is to directly modify, check the length, and access specific elements within the array.

Create an array called cities with the following city names:
- "Shanghai";
- "Sydney";
- "Toronto";
- "Frankfurt".
Modify the city name at index 2 to "Miami" directly within the array.
Log the length of the cities array using console.log().
Retrieve and log the last city name in the array using console.log().


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// Task 1: Initial array
const cities = ___;

// Task 2: Modify a city name
cities___ = "Miami";

// Modified array
console.log(cities); // Output: Shanghai, Sydney, Miami, Frankfurt

// Task 3: Log array length
console.log("Array length:", ___); // Output: Array length: 4

// Task 4: Access and log the last city
console.log("Last city:", ___); // Output: Last city: Frankfurt

Expected Output:

Use square brackets [] to create an array.
Separate each element with the comma ,.
Use console.log() to log the data.
Use square brackets [] within the element index to access the element and change its value.
Use the keyword length to get the array length.


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// Task 1: Initial array
const cities = ["Shanghai", "Sydney", "Toronto", "Frankfurt"];

// Task 2: Modify a city name
cities[2] = "Miami";

// Modified array
console.log(cities); // Output: Shanghai, Sydney, Miami, Frankfurt

// Task 3: Log array length
console.log("Array length:", cities.length); // Output: Array length: 4

// Task 4: Access and log the last city
console.log("Last city:", cities[cities.length - 1]); // Output: Last city: Frankfurt

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Section 4. Chapter 4