Introduction to JavaScript

Course Content

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

The `else if` Clause

In addition to the else clause, conditional statements support an else if clause, which can be used to define alternative conditions if the initial if condition is false.

The general syntax is as follows:

if(expression) {
  // Code … (executed if the expression is true)
} else if(expression) {
  // Fallback Code … 
  //(executed if the previous condition is false, and this one is true)
}

As seen in the general syntax, the else if clause takes a boolean expression, which is evaluated when the condition before it turns out to be false.

We can chain multiple else if clauses to form an if-else if chain:

if(expression) {
  // … (executed if the first condition is true)
} else if(expression) {
  // … (executed if the first condition is false and this is true)
} else if(expression) {
  // … (executed if previous conditions are false and this is true)
} else {
  // … (executed if all previous conditions are false)
}

As shown in the code above, we can optionally add the else clause at the end. This block is executed only when all the previous conditions evaluate to false.

The following example demonstrates the usage of this syntax:


              123456789
            
let number = 50;

if (number < 20) {
  console.log("The number is less than 20.");
} else if (number === 20) {
  console.log("The number is exactly 20.");
} else {
  console.log("The number is greater than 20.");
}

Everything was clear?

Thanks for your feedback!

Section 3. Chapter 10

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Course Content

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

The `else if` Clause

In addition to the else clause, conditional statements support an else if clause, which can be used to define alternative conditions if the initial if condition is false.

The general syntax is as follows:

if(expression) {
  // Code … (executed if the expression is true)
} else if(expression) {
  // Fallback Code … 
  //(executed if the previous condition is false, and this one is true)
}

As seen in the general syntax, the else if clause takes a boolean expression, which is evaluated when the condition before it turns out to be false.

We can chain multiple else if clauses to form an if-else if chain:

if(expression) {
  // … (executed if the first condition is true)
} else if(expression) {
  // … (executed if the first condition is false and this is true)
} else if(expression) {
  // … (executed if previous conditions are false and this is true)
} else {
  // … (executed if all previous conditions are false)
}

As shown in the code above, we can optionally add the else clause at the end. This block is executed only when all the previous conditions evaluate to false.

The following example demonstrates the usage of this syntax:


              123456789
            
let number = 50;

if (number < 20) {
  console.log("The number is less than 20.");
} else if (number === 20) {
  console.log("The number is exactly 20.");
} else {
  console.log("The number is greater than 20.");
}

Everything was clear?

Thanks for your feedback!

Section 3. Chapter 10

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