Introduction to JavaScript

Kursusindhold

Introduction to JavaScript

Introduction to JavaScript

1. Getting Started

First Javascript Console Application Challenge: Showing some Output Challenge: Outputing Multiple Lines Dealing with Numbers Challenge: Working with Numbers Challenge: Calculating the Speed of a Car Challenge: Calculating Area of a Trapezium Outputting Multiple Values Challenge: Consoling Meaningful Output How to Use Comments in Javascript?Challenge: Adding a Comment Multi-Line Comments Challenge: Commenting out Code What Is JavaScript anyway?

2. Manipulating Data

Storing Data Challenge: Declaring a Variable Challenge: Accessing Data From a Variable Challenge: Fixing Variable Names Challenge: Reassigning a Variable Constants Challenge: Declaring & Using Constants Performing Arithmetic On Variables Challenge: Making a Salary Calculator Challenge: Adjusting Salary with a Bonus Exploring Primitive Data Types Challenge: Declaring a Boolean Value How different Data Types Interact Challenge: Concatenating Strings Challenge: Creating User Profile & Activity Details

3. Conditional Statements

Comparison Operators Challenge: Checking Age Eligibility The `if` Statement Challenge: Weather-Based Outfit Recommender Challenge: Even or Odd Nested Conditional Statements The `else` Clause Challenge: Improving Even or Odd Checker Challenge: Temperature Advisor The `else if` Clause Challenge: Grade Categorizer ` AND` Logical Operator Challenge: Checking if a Number is Even and Positive OR Logical Operator Challenge: Accessing Control System

4. Mastering Functions

What Are Functions?Challenge: Simple Function Challenge: Calculating the Speed of a Car Scopes Passing Data into Functions Challenge: Fixing the Speed Function Challenge: Improving the Grade Categorizer Task: Defining a Compound Function Returning Data from Functions Default Values Challenge: Email Auto-Responder with Default Parameters

5. Exploring Arrays

What Are Arrays?Challenge: Defining An Array Challenge: Indexing Adding Values to an Array Challenge: Pushing Elements to an Array Removing Elements from an Array Challenge: Practicing `pop` & `shift`The `length` Property Challenge: Counting Elements The `includes` Method Challenge: Searching for Animals in the Zoo

6. Discovering Loops

The `for` Loop Task: Printing a Sequence The `while` Loop Challenge: Printing Fibonacci Sequence The `do-while` Loop Challenge: Random Multiple of 7 Using Loops with Arrays Challenge: Finding the Average Price of Items Summary

Using Loops with Arrays

Loops enable us to efficiently go through all or specific elements of an array.

For example, we can use a for loop to iterate through all elements of an array and output them:


              12345
            
let numbers = [1, 1, 2, 3, 5, 8, 13, 21];

for(let i = 0; i < numbers.length; i++) {
  console.log("Element " + (i + 1) + " of the array is: " + numbers[i]);
}

This is especially useful when we need to perform an operation on multiple elements in an array:


              1234567
            
let numbers = [1, 1, 2, 3, 5, 8, 13, 21];

console.log("Before:", numbers);
for(let i = 0; i < numbers.length; i++) {
  numbers[i] *= 2;
}
console.log("After:", numbers);

We can use a while or a do-while loop for this purpose as well, however, that is not the convention.


              123456789
            
let numbers = [1, 1, 2, 3, 5, 8, 13, 21];

console.log("Before:", numbers);
let i = 0;
while(i < numbers.length) {
  numbers[i] *= 2;
  i += 1;
}
console.log("After:", numbers);

Even though the same results can be achieved using while or do-while loops, it is recommended to use a for loop when iterating through arrays because it is the conventional and more readable approach.

1. What does the following code output?

2. Does the following code modify the original array?

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Sektion 6. Kapitel 7

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Kursusindhold

Introduction to JavaScript

Introduction to JavaScript

1. Getting Started

First Javascript Console Application Challenge: Showing some Output Challenge: Outputing Multiple Lines Dealing with Numbers Challenge: Working with Numbers Challenge: Calculating the Speed of a Car Challenge: Calculating Area of a Trapezium Outputting Multiple Values Challenge: Consoling Meaningful Output How to Use Comments in Javascript?Challenge: Adding a Comment Multi-Line Comments Challenge: Commenting out Code What Is JavaScript anyway?

2. Manipulating Data

Storing Data Challenge: Declaring a Variable Challenge: Accessing Data From a Variable Challenge: Fixing Variable Names Challenge: Reassigning a Variable Constants Challenge: Declaring & Using Constants Performing Arithmetic On Variables Challenge: Making a Salary Calculator Challenge: Adjusting Salary with a Bonus Exploring Primitive Data Types Challenge: Declaring a Boolean Value How different Data Types Interact Challenge: Concatenating Strings Challenge: Creating User Profile & Activity Details

3. Conditional Statements

Comparison Operators Challenge: Checking Age Eligibility The `if` Statement Challenge: Weather-Based Outfit Recommender Challenge: Even or Odd Nested Conditional Statements The `else` Clause Challenge: Improving Even or Odd Checker Challenge: Temperature Advisor The `else if` Clause Challenge: Grade Categorizer ` AND` Logical Operator Challenge: Checking if a Number is Even and Positive OR Logical Operator Challenge: Accessing Control System

4. Mastering Functions

What Are Functions?Challenge: Simple Function Challenge: Calculating the Speed of a Car Scopes Passing Data into Functions Challenge: Fixing the Speed Function Challenge: Improving the Grade Categorizer Task: Defining a Compound Function Returning Data from Functions Default Values Challenge: Email Auto-Responder with Default Parameters

5. Exploring Arrays

What Are Arrays?Challenge: Defining An Array Challenge: Indexing Adding Values to an Array Challenge: Pushing Elements to an Array Removing Elements from an Array Challenge: Practicing `pop` & `shift`The `length` Property Challenge: Counting Elements The `includes` Method Challenge: Searching for Animals in the Zoo

6. Discovering Loops

The `for` Loop Task: Printing a Sequence The `while` Loop Challenge: Printing Fibonacci Sequence The `do-while` Loop Challenge: Random Multiple of 7 Using Loops with Arrays Challenge: Finding the Average Price of Items Summary

Using Loops with Arrays

Loops enable us to efficiently go through all or specific elements of an array.

For example, we can use a for loop to iterate through all elements of an array and output them:


              12345
            
let numbers = [1, 1, 2, 3, 5, 8, 13, 21];

for(let i = 0; i < numbers.length; i++) {
  console.log("Element " + (i + 1) + " of the array is: " + numbers[i]);
}

This is especially useful when we need to perform an operation on multiple elements in an array:


              1234567
            
let numbers = [1, 1, 2, 3, 5, 8, 13, 21];

console.log("Before:", numbers);
for(let i = 0; i < numbers.length; i++) {
  numbers[i] *= 2;
}
console.log("After:", numbers);

We can use a while or a do-while loop for this purpose as well, however, that is not the convention.


              123456789
            
let numbers = [1, 1, 2, 3, 5, 8, 13, 21];

console.log("Before:", numbers);
let i = 0;
while(i < numbers.length) {
  numbers[i] *= 2;
  i += 1;
}
console.log("After:", numbers);

Even though the same results can be achieved using while or do-while loops, it is recommended to use a for loop when iterating through arrays because it is the conventional and more readable approach.

1. What does the following code output?

2. Does the following code modify the original array?

Var alt klart?

Tak for dine kommentarer!

Sektion 6. Kapitel 7

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