var age = 18; // number
var name = "Jane"; // string
var name = {first:"Jane", last:"Doe"}; // object
var truth = false; // boolean
var sheets = ["HTML","CSS","JS"]; // array
var a; typeof a; // undefined
var a = null; // value null
Number // var age = 18
String // var name = "codepadding"
Boolean // var prgramming = true
Object // var fullName = {first:"Code", last:"Padding"};
Undefined // var program; typeof program
array // var language = ["javaScaript","dart"]
null // var error = null
/*JavaScript data types*/
//string
var string = 'ASCII text';
//int
var integer = 123456789;
//float
var float = 123.456;
//boolean, can be true or false
var t = true;
var f = false;
//undefined
var undef;//defaults to undefined
var undef = undefined;//not common, use null
//null
var nul = null;
//array
var arr = ['Hello','my','name','is','Dr.Hippo',123,null];
//object
var person = {'name':'John Smith','age':27};
//function
var fun = function(){
return 42;
}
//String Data Type
var strSingle = 'John'; //String with single quotes
var strDouble = "Bob"; //String with double quotes
//Number Data Type
var num = 25; //Integer
var flo = 80.5; //Floating-point number
var exp = 4.25e+6; //Exponential notation, this equates to 4250000
//Boolean Data Type
var isReading = true; //Yes, I'm reading
var isSleeping = false; //No, I'm not sleeping
//Undefined Data Type
var undef; //If a value is never assigned, any output will be 'undefined'
//Null Data Type
var noValue = null; //Null meaning that it is has no value, not the same as 0 or ""
//Object Data Type
var emptyObject = {};
var person = {"name": "Clark", "surname": "Kent", "age": "36"}; //The quotes around the propety name can be omitted if the property name is a valid JS name
var car = { //Same as person but easier to read
model: "BMW X3", //Example with quotes around property name ommitted
color: "white",
doors: 5
}
//Array Data Type
var emptyArray = []; //An array can be of any data types (string, number, boolean, etc.)
var array = ["One", "Two"] //String array, note the index of the first element is 0
//Function Data Type
var func = function() { //Calling the function: func();
alert("Code excuted"); //Outputs: Code executed
}
var funcVar = function(amount) { //Calling the function: funcVar(6);
alert("Code excuted " + amount + " times"); //Outputs: Code executed 6 times (if input was 6)
}
//Typeof Operator
typeof variable; //Returns the data type of the variable
// What are JavaScript Data Types?
let name = "Chetan"; // string
let age = 30; // number
let fullName = {first:"Chetan", last:"Nada"}; // object
let truth = false; // boolean
let language = ["HTML","CSS","JS"]; // array
let x; typeof x; // undefined
let val = null; // value null
dataTypes = {
Numbers = 1,2,3, 100, 3.14
Strings = 'Hello, World' "helloworld@gmail.com
Boolean = true / false
Null = 'Explicitly set a variable with no Value'
Undefined = 'For variable that have not yet been defined'
Object = 'Complex data structures - Arrays, Dates, Literals etc'
Symbol = 'Used with objects' // usually not needed
}
var age = 18; // number
var name = "Jane"; // string
var name = {first:"Jane", last:"Doe"}; // object
var truth = false; // boolean
var sheets = ["HTML","CSS","JS"]; // array
var a; typeof a; // undefined
var a = null; // value null
//There are 7 data types in JS
//They're split in two categories - (Primitives and Complex Types)
//Primives
string, number, boolean, null, undefined
//Complex types
Object, Function
let age = 16; // number
let name = "John"; // string
let name = {first:"Jane", last:"Duo"}; // object
let truth = false; // boolean
let sheets = ["HTML","CSS","JS"]; // array
let a; typeof a; // undefined
let a = null; // null
// Data types in JavaScript
// In JavaScript, there are seven fundamental data types:
// first 6 is primitive data types (string, number, boolean, null, undefined, Symbol) and last one is complex data types (Object).
// Number: Any number, including numbers with decimals: 4, 8, 1516, 23.42.
let num = 23;
let num1 = 1.4;
// String: Any grouping of characters on your keyboard (letters, numbers, spaces, symbols, etc.) surrounded by single quotes: ' ... ' or double quotes " ... ", though we prefer single quotes. Some people like to think of string as a fancy word for text.
let name = 'chetan';
let name1 = 'ujesh';
// Boolean: This data type only has two possible values— either true or false (without quotes). It’s helpful to think of booleans as on and off switches or as the answers to a “yes” or “no” question.
let value = true;
let value1 = false;
// Null: This data type represents the intentional absence of a value, and is represented by the keyword null (without quotes).
let ans = null;
// Undefined: This data type is denoted by the keyword undefined (without quotes). It also represents the absence of a value though it has a different use than null. undefined means that a given value does not exist.
let que;
let coding;
// Symbol: A Symbol is a unique and immutable primitive value and may be used as the key of an Object property.
let sym = Symbol();
let sym1 = Symbol('foo');
// Object: An object contains properties, defined as a key-value pair. A property key (name) is always a string, but the value can be any data type, like strings, numbers, booleans, or complex data types like arrays, function and other objects.
// Array
let myArr = ['My','Name','is','Chetan'];
// Object
let person = {'firsName':'Chetan', lastName:'Nada' 'age':32};
// Function
let myFunction = function(){
return "Thanks for Reading Data types in JavaScript";
}