Introduction to JavaScript

Course Content

Introduction to JavaScript

Introduction to JavaScript

1. JavaScript Fundamentals

About JavaScript Understanding JavaScript Syntax Challenge: Console Output in JavaScript Using Comments to Document Code Challenge: Write a Single-Line Comment Challenge: Write a Multi-Line Comment

2. Variables and Data Types in JavaScript

Understanding Variables in JavaScript Challenge: Define the Variable Using const for Constants Exploring JavaScript Data Types Working with null in JavaScript Introduction to Arrays Array Methods and Manipulation Challenge: Perform Array Operations

3. Performing Operations in JavaScript

Understanding Assignment Operators Mathematical Operations in JavaScript Assignment Operators in JavaScript Increment and Decrement Operators Challenge: Variable Operations Practice Comparison Operators in JavaScript Logical Operators Explained Challenge: Compare Variables in JavaScript Concatenating Strings in JavaScript Challenge: Build Sentences with JavaScript

4. Controlling Program Flow with Conditional Statements

Mastering if Statements in JavaScript Using else for Alternative Outcomes Applying else if for Multiple Conditions Challenge: Determine Sizes with Conditionals

5. Looping Through Data in JavaScript

Understanding the while Loop in JavaScript Using the do while Loop for Iteration Challenge: Print Numbers from 5 to 9 Mastering the for Loop in JavaScript Challenge: Console Tigers with Loops Breaking Out of Loops with break Skipping Iterations with continue Challenge: Stop and Skip in Loops

6. Functions in JavaScript

What Are Functions in JavaScript?Defining Functions in JavaScript Challenge: Write a Function – My Name Using Function Arguments Effectively Returning Values from Functions Challenge: Create a Sum Function Course Summary & Next Steps

Understanding the while Loop in JavaScript

Loop Types

Loops are structures that repeatedly execute a code block while a specific condition is true. In JavaScript, there are three types of loops:

while;
do-while;
for.

Let's explore each of them in detail.

while Loop

The while loop is the simplest type of loop. It continues to execute a code block as long as the specified condition remains true.

To create a while loop, use the while keyword followed by a condition in parentheses and enclose the code block in curly braces. The syntax is similar to that of an if statement:

javascript

Here's an example:


              123456
            
let a = 5;

while (a <= 10) {
  console.log("a =", a);
  a++;
}

In this example, the while loop's code block executes six times:

Initially, the variable a is set to 5;
The loop condition is a <= 10, which is true, so the code block is executed;
After each execution, the variable a is incremented by 1;
The loop continues to execute as long as the condition remains true.

Note

The while loop checks the condition before executing the code block. If the condition is initially false, the code block will not be executed.

Note

Be cautious with the condition! If the condition always evaluates to true, the loop will never break, resulting in an infinite loop, which can cause your program to hang or become unresponsive.

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Section 5. Chapter 1

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