script.js

//! JavaScrirpt Variables
//* var, let, const
// ^^^^^^^^^^^^^^^^^^^^^

//! First "var"
// var a;         //* Delcare karna
// var b = 10;    //* Delcare and intialize
// var            //* Function scoped hota hai
// var            //* You can redelcare and reintialize
// var            //* window object ke sath attach hota hai
// var            //* hoisting hota hai

//! Second "let"
// let c;         //* Delcare karna
// let d = 10;    //* Delcare and intialize
// let            //* block scope hota hai
// let            //* You can just reintialize
// let            //* hoisting hota hai but you can not access it before initialization

//! third "const"
// const a;       //* Esa declare karna allowed nahi hai
// const b = 10;  //* Delcare and intialize
// const          //* block scope hota hai
// const          //* You can not reintialize and redeclare
// const          //* hoisting hota hai but you can not access it before initialization

// ==>---------------------------------------------------------------------------------------------<== //

//! JavaScript Data Types
// Primitives: string, number, boolean, null, undefined, symbol, bigint
// reference: object, array, function
// Non-Primitive / Reference Data Types: object, array, function

//! ==> Primitive Data Types <== //
//! 1. ( String )
//* String text/data ko represent karta hai
// let a = "Rafay";
// let b = 'Karachi';
// let c = `Pakistan`;


//! 2. ( Number )
//* Number integer aur decimal dono values ko represent karta hai
// let age = 18;
// let price = 99.99;


//! 3. ( Boolean )
//* Boolean ki sirf 2 values hoti hain: true aur false
// let isLoggedIn = true;
// let isAdmin = false;


//! 4. ( Undefined )
//* Variable declare ho lekin usko koi value assign na ki gayi ho
// let username;
// console.log(username); // undefined


//! 5. ( Null )
//* Intentionally empty ya no value ko represent karta hai
// let selectedUser = null;


//! 6. ( Symbol )
// Unique value/identifier create karne ke liye use hota hai
// let id = Symbol("id");


//! 7. ( BigInt )
// Bohat bade integers ko store karne ke liye use hota hai
// let bigNumber = 123456789012345678901234567890n;


//! ==> Non-Primitive / Reference Data Type <== //
//! 8. ( Object )
//* Key-value pairs mein data store karta hai
// let user = {
//     name: "Rafay",
//     age: 18
// };


//! ( Array )
//* Multiple values ko ek variable mein store karta hai
// let fruits = ["Apple", "Mango", "Banana"];


//! ( Function )
//* Function bhi JavaScript mein ek Object hota hai
// function greet() {
//     console.log("Hello");
// }


//! ==> Important Point <== //

// Primitive:
// string
// number
// boolean
// undefined
// null
// symbol
// bigint

// Non-Primitive / Reference:
// object
// array
// function


//! ==> typeof Operator <== //

// typeof se hum kisi value ka data type check kar sakte hain

//* console.log(typeof "Rafay");       // string
//* console.log(typeof 100);           // number
//* console.log(typeof true);          // boolean
//* console.log(typeof undefined);     // undefined
//* console.log(typeof 123n);          // bigint
//* console.log(typeof Symbol("id"));  // symbol
//* console.log(typeof {});            // object
//* console.log(typeof []);            // object
//* console.log(typeof function(){});  // function


//! ==> Important JavaScript Weirdness <== //

// typeof null "object" return karta hai
// console.log(typeof null); // object

// Array technically Object hota hai
// console.log(typeof []); // object

// Array check karne ka correct method:
// console.log(Array.isArray([])); // true

//! ==> JavaScript operators <== //
//* Arithmetic Operators: ( +, -, *, **, /, %, ++, -- )
//* Comparison Operators: ( =, ==, ===, !=, !==, >, <, >=, <= )
//* Assignment Operators: ( =, +=, -=, *=, /=, %= )
//* Logical Operators: ( &&, ||, ! )
//* unary Operators: ( typeof, void, delete )
//* ternary Operators: ( condition ? expr1 : expr2 )

//!Arithmetic Operators
//* +, -, *, **, /, %, ++, --
// ( + ) adition karta hai or concatenate bhi karta hai
// ( - ) subtraction karta hai
// ( * ) multiplication karta hai
// ( ** ) exponentiation karta hai
// ( / ) division karta hai
// ( % ) modules, modulo karta hai
// ( ++ ) increment karta hai
// ( -- ) decrement karta hai


// console.log(10 + "11");    // "1011"
// console.log(20 - 11);      // 9
// console.log(10 * 2);       // 20
// console.log(2 ** 3);       // 8
// console.log(10 / 2);       // 5
// console.log(10 % 3);       // 1
// console.log(10++);         // 11
// console.log(10--);         // 9
// console.log(++10);         // 11
// console.log(--10);         // 9

//! Comparison Operators
//* ==, ===, !=, !==, >, <, >=, <=
// ( = ) assignment operator hai, variable ko value assign karta hai value dal ta hai
// ( == ) values ko compare karta hai, type coercion ke saath
// ( === ) values ko compare karta hai, type coercion ke bina
// ( != ) not equal to hota hai, type coercion ke saath
// ( !== ) strict not equal to hota hai, type coercion ke bina
// ( > ) greater than hota hai
// ( < ) less than hota hai
// ( >= ) greater than or equal to hota hai
// ( <= ) less than or equal to hota hai

// console.log(10 == "11");   // true
// console.log(10 === 10);    // true
// console.log(10 != 10);     // false
// console.log(10 !== 10);    // false
// console.log(10 > 5);       // true
// console.log(10 < 5);       // false
// console.log(10 >= 5);      // true
// console.log(10 <= 5);      // false


// let x = 10;
// let y = 20;

// if (x > 5 && y < 30) {
//     console.log("A");
// } else{
//     console.log("B");
// }

// let temp = 35;

// if (!(temp < 30)) {
//     console.log("Hot outside.");
// } else {
//     console.log("pleasant outside.");
// }

// let marks = 78;

// let result =
//       marks
//     >= 80
//     ? "A+"
//     : marks >= 70
//     ? "A"
//     : marks >= 60
//     ? "B"
//     : "Fail";

// console.log(result);

// let num = -8;

// let result = num > 0
//     ? (num % 2 === 0 ? "Positive Even" : "Positive Odd")
//     : "Not Positive";

// console.log(result);

// let age = 17;

// let status = age >= 18
//     ? "Adult"
//     : age >= 13
//     ? "Teenager"
//     : "Child";

// console.log(status);

// let marks = 75;
// let attendance = 80;

// let result = marks >= 75 && attendance >= 80 ? "Pass" : "Fail";

// console.log(result);

// let rafayAge = 10;
// let aliAge = 20;

// let result = rafayAge > aliAge ? rafayAge : aliAge;

// console.log(result);

// let temperature = 35;

// let result = temperature >= 40
//     ? "Very Hot"
//     : temperature >= 30
//     ? "Hot"
//     : temperature >= 20
//     ? "Normal"
//     : "Cold";

// console.log(result);

// let a = 15;
// let b = 4;

// let result = a % b === 0
//     ? "Divisible"
//     : "Not Divisible";

// console.log(result);

// let num = 12;

// let result = num > 10
//     ? num % 2 === 0
//         ? "Greater than 10 and Even"
//         : "Greater than 10 and Odd"
//     : "10 or Less";

// console.log(result);

// function getGrade(score) {
//     if (score >= 90 && score <= 100) {
//         return "A+"
//     } else if (score >= 80 && score <= 89) {
//         return "A"
//     }
//     else if (score >= 70 && score <= 79) {
//         return "B"
//     }
//     else if (score >= 60 && score <= 69) {
//         return "C"
//     }
//     else if (score >= 33 && score <= 59) {
//         return "D"
//     } 
//     else if (score >= 0 && score <= z) {
//         return "Fail"
//     }
// }