[javascript]

29 Nov 2023

javascript

JavaScript is a popular programming language that is widely used for creating interactive web pages. It is a high-level, interpreted language that runs on web browsers.

In this blog post, I will introduce you to the basics of JavaScript and provide you with some example code to help you get started.

Variables
Data Types
Operators
Control Flow
Functions
Objects

Variables

Variables are used to store values in JavaScript. You can declare a variable using the var, let, or const keyword.

var x = 5; // Declaration and initialization of a variable
let y = 10;
const z = 15; // Constant variable

x = 7; // Reassigning a value to a variable

console.log(x); // Output: 7

Data Types

JavaScript supports several data types including numbers, strings, booleans, objects, arrays, and more.

var num = 5; // Number
var str = "Hello"; // String
var bool = true; // Boolean

var obj = {
  name: "John",
  age: 30
}; // Object

var arr = [1, 2, 3, 4, 5]; // Array

console.log(num, str, bool, obj, arr);

Operators

JavaScript provides a variety of operators for performing arithmetic, comparison, logical, and other operations.

var x = 5;
var y = 10;

var sum = x + y; // Addition
var difference = x - y; // Subtraction
var product = x * y; // Multiplication
var quotient = y / x; // Division

console.log(sum, difference, product, quotient);

Control Flow

Control flow statements allow you to control the execution of your JavaScript code.

var x = 5;

if (x > 0) {
  console.log("Positive");
} else if (x < 0) {
  console.log("Negative");
} else {
  console.log("Zero");
}

var i = 0;

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

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

Functions

Functions in JavaScript allow you to encapsulate a block of code that can be reused.

function sayHello(name) {
  console.log("Hello, " + name + "!");
}

sayHello("John"); // Output: Hello, John!

Objects

Objects allow you to group related data and functions together.

var person = {
  name: "John",
  age: 30,
  sayHello: function() {
    console.log("Hello, my name is " + this.name + ".");
  }
};

console.log(person.name); // Output: John
console.log(person.age); // Output: 30
person.sayHello(); // Output: Hello, my name is John.

I hope this introduction to JavaScript has provided you with a good starting point. JavaScript is a powerful language that can add interactivity and dynamic behavior to your web pages.

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