JavaScript

Table of Contents

1. Introduction to Client-Side Scripting with JavaScript

JavaScript is a versatile scripting language used for creating dynamic content on web pages. It is primarily executed on the client’s browser, enabling interactive and responsive user interfaces.

2. Variables

Variables are used to store and manipulate data. In JavaScript, you can declare variables using the var, let, or const keyword.

var name = "John";
let age = 25;
const PI = 3.14;

3. Functions

Functions are blocks of reusable code. They are defined using the function keyword.

function greet(name) {
  alert("Hello, " + name + "!");
}

// Function invocation
greet("John");

4. Conditions

Conditional statements allow you to make decisions in your code based on certain conditions.

var age = 18;

if (age >= 18) {
  console.log("You are an adult.");
} else {
  console.log("You are a minor.");
}

5. Loops and Repetition

Loops are used to repeatedly execute a block of code.

For loop

for (var i = 0; i < 5; i++) {
  console.log(i);
}

While loop

var i = 0;
while (i < 5) {
  console.log(i);
  i++;
}

Do while loop

var i = 0;
do {
  console.log(i);
  i++;
} while (i < 5);

6. Pop-up Boxes

Pop-up boxes are often used for user interactions. JavaScript provides three types: alert, confirm, and prompt.

Alert

alert("This is an alert!");

Confirm

var result = confirm("Do you want to proceed?");
if (result) {
  console.log("User clicked OK.");
} else {
  console.log("User clicked Cancel.");
}

Prompt

var name = prompt("Please enter your name:", "John Doe");
console.log("User entered: " + name);

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