Introduction to JavaScript

Introduction to JavaScript

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1. Basic Concepts

Discover the fundamentals of JavaScript, including its purpose and syntax. Learn how to work with the console for output and use comments to organize and document your code. These foundational skills will prepare you for a deeper exploration of JavaScript's capabilities.

About JavaScript

Challenge: Console Output

Challenge: Single-line Comment

Challenge: Multi-line Comment

2. Variables and Data Types

Explore the building blocks of JavaScript by distinguishing between literals and variables. Understand the core data types, including `null` and arrays, and learn how to manipulate them using array methods.

Challenge: Defining the Variable

Data Types Overview

Challenge: Array Operations

3. Basic Operations

Learn how to manipulate JavaScript's data types through essential operations. Master assignment, mathematical operations, incrementing and decrementing, comparisons, logical operations, and string concatenation.

Mathematical Operations

Operations with Assignment

Increment and Decrement

Challenge: Variable Operations

Comparison Operations

Logical Operations

Challenge: Comparing Variables

String Concatenation

Challenge: Sentence Building

4. Conditional Statements

Discover how to control the flow of your programs with conditional statements. Master `if`, `else`, and `else if` to instruct JavaScript on making decisions and executing code based on different conditions.

Challenge: Determining Size

5. Loops

Streamline your code by mastering JavaScript's looping structures. Explore `while`, `do while`, and `for` loops, and learn how to control their behavior using `break` and `continue`. Unlock the power of loops to perform repetitive tasks efficiently.

Challenge: Printing Numbers from 5 to 9

Challenge: Tigers

Challenge: Stopping and Skipping

6. Functions

Discover the power of functions in JavaScript. Learn how to define functions, work with arguments, and use the `return` statement to create reusable and efficient code. Mastering functions will enhance your ability to write clean and modular programs.

What is a Function?

Challenge: My Name

Course Content

Introduction to JavaScript

Introduction to JavaScript

Logical Operations

Now, let's explore logical operations. Logical operations are used to manipulate and make decisions based on boolean values.

Logical Operators

There are three logical operators in JavaScript:

AND (&&);
OR (||);
NOT (!).

AND (&&)

The AND (&&) logical operator returns true only when both values it operates on are true. The result is false if any value is false.


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console.log(true && true);
console.log(true && false);
console.log(false && true);
console.log(false && false);

The AND (&&) operator requires all values to be true to return true.

OR (||)

The OR (||) logical operator returns true if at least one of the values is true. It returns false only when both values are false.


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console.log(true || true);
console.log(true || false);
console.log(false || true);
console.log(false || false);

The OR (||) operator returns false only when both values are false.

NOT (!)

The NOT (!) operator inverts the boolean value. It turns true into false and false into true.


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console.log(!true);
console.log(!false);

Using Logical Operators

Logical operators are often used to combine conditions. For example, to check if two values are greater than 4 or greater than 1, you can use the AND (&&) operator.


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let a = 5, b = 3;

console.log(a > 4 && b > 4);
console.log(a > 1 && b > 1);

Priority

Logical operations have a lower priority than comparison operations, which, in turn, have a lower priority than mathematical operations.

Note

Similar to other operations, you can use parentheses () to adjust the priority of execution.

1. What will be the output?

2. What will be the output?

3. What will be the output?

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Section 3. Chapter 7

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