practice.js

// console.log("Hi there");
//it just prints out hi there
/*this is a 
multiline comment*/
//this is a
//multiple comment

// var a;
// a = 10;
// var b = "John";

//8 basic data types in javascript

// const message = "hello";
// message = 12345;

// console.log(message);

//1 Number

// let n = 123;
// n = 12.345;
// console.log(n);

//specific numeric numbers
//Infinity
// alert(1 / 0);
// console.log(1 / 0);
// console.log(Infinity);

//NaN

// console.log(NaN + 1);
// console.log(NaN * 3);
// console.log("not a number" / 2 - 1);

// console.log(NaN * 0);
// console.log(NaN ** 0);  //exception

// //2 BigInt
// const bigInt = 9007199254740991n;

// console.log(bigInt);

//3 String
//simple quotes
// let str = "Hello";
// let str2 = "Single Quotes";

// //extended functionality embeds a value ${}
// let str3 = `${str} , how are you doing`;

// console.log(str3);

// console.log(`the result is ${1 + 2}`);
// console.log("the substraction is ${2 - 1}");

//4 Boolean (logical type)

// let isChecked = false;

// let isGreater = 4 > 1;
// console.log(isGreater);

//5 Null
// let age = null;
// console.log(age);
//its just a special value which represents nothing, empty or a value unknown

//6 undefined
//it means value is not defined

//7 Object and Symbols nom-primitive
//used for more complex data structures

//Type Coversions

// alert(8);

//String Conversion

// let value = true;
// value = String(value);
// console.log(typeof value);

//Numeric Conversion

// alert("6" / "2");

// let str = "123";

// let num = Number(str);

// console.log(typeof num);

// let age = Number("A string instead of a number");
// console.log(age);

// console.log(Number("    123     "));

// console.log(Number(true));
// console.log(Number("123a"));

// console.log(Number(undefined));

// console.log(Number(null));