{"id":62,"date":"2024-11-06T03:59:39","date_gmt":"2024-11-06T03:59:39","guid":{"rendered":"https:\/\/techkubo.com\/javascript\/?p=62"},"modified":"2025-05-13T10:59:58","modified_gmt":"2025-05-13T10:59:58","slug":"javascript-data-types","status":"publish","type":"post","link":"https:\/\/techkubo.com\/javascript\/javascript-data-types\/","title":{"rendered":"JavaScript Data Types"},"content":{"rendered":"\n

Primitive Data Types<\/strong><\/h2>\n\n\n\n

JavaScript has several primitive data types that represent simple values.<\/p>\n\n\n\n

<\/p>\n\n\n\n

1. Number<\/strong><\/h3>\n\n\n\n

The number<\/code> data type represents both integer and floating-point numbers.<\/p>\n\n\n\n

let age = 25;  \/\/ Integer\nlet price = 19.99;  \/\/ Floating-point\nconsole.log(typeof age);  \/\/ Output: "number"\nconsole.log(typeof price);  \/\/ Output: "number"<\/pre><\/div>\n\n\n\n
2. String<\/strong><\/h3>\n\n\n\n
The string<\/code> data type is used to represent text. Strings are enclosed in single quotes ('<\/code>), double quotes (\"<\/code>), or backticks (`<\/code>).<\/p>\n\n\n\n
let name = "John";\nlet greeting = 'Hello, World!';\nlet template = `My name is ${name}`;\nconsole.log(typeof name);  \/\/ Output: "string"\nconsole.log(typeof greeting);  \/\/ Output: "string"\nconsole.log(template);  \/\/ Output: "My name is John"<\/pre><\/div>\n\n\n\n
3. Boolean<\/strong><\/h3>\n\n\n\n
The boolean<\/code> data type represents a logical value: true<\/code> or false<\/code>.<\/p>\n\n\n\n
let isJavaScriptFun = true;\nlet isItRaining = false;\nconsole.log(typeof isJavaScriptFun);  \/\/ Output: "boolean"\nconsole.log(typeof isItRaining);  \/\/ Output: "boolean"<\/pre><\/div>\n\n\n\n
4. Undefined<\/strong><\/h3>\n\n\n\n
A variable that has been declared but not assigned a value is of type undefined<\/code>.<\/p>\n\n\n\n
let uninitialized;\nconsole.log(typeof uninitialized);  \/\/ Output: "undefined"<\/pre><\/div>\n\n\n\n
5. Null<\/strong><\/h3>\n\n\n\n
The null<\/code> data type represents an intentional absence of any object value. It is treated as an object type, but this is actually a bug in JavaScript.<\/p>\n\n\n\n
let emptyValue = null;\nconsole.log(typeof emptyValue);  \/\/ Output: "object"<\/pre><\/div>\n\n\n\n
6. Symbol<\/strong><\/h3>\n\n\n\n
The symbol<\/code> data type is used to create unique identifiers for objects.<\/p>\n\n\n\n
let uniqueId = Symbol("id");\nconsole.log(typeof uniqueId);  \/\/ Output: "symbol"<\/pre><\/div>\n\n\n\n
<\/p>\n\n\n\n
Complex Data Type<\/strong><\/h2>\n\n\n\n
JavaScript also has a complex data type known as Object<\/code>.<\/p>\n\n\n\n
<\/p>\n\n\n\n
Object<\/strong><\/h3>\n\n\n\n
Objects are collections of key-value pairs. They can store multiple values as properties.<\/p>\n\n\n\n
let person = {\n    firstName: "John",\n    lastName: "Doe",\n    age: 30,\n    isEmployed: true\n};\nconsole.log(typeof person);  \/\/ Output: "object"\nconsole.log(person.firstName);  \/\/ Output: "John"<\/pre><\/div>\n\n\n\n
<\/p>\n\n\n\n
JavaScript Data Types Example Code<\/strong><\/h2>\n\n\n\n
Explanation of Code:<\/strong><\/p>\n\n\n\n
    \n
  • Number<\/strong>: Declares a variable age<\/code> with a numeric value.<\/li>\n\n\n\n
  • String<\/strong>: Declares a variable name<\/code> with a string value.<\/li>\n\n\n\n
  • Boolean<\/strong>: Declares a variable isStudent<\/code> with a boolean value.<\/li>\n\n\n\n
  • Undefined<\/strong>: Declares a variable city<\/code> without assigning a value.<\/li>\n\n\n\n
  • Null<\/strong>: Declares a variable car<\/code> with a null value.<\/li>\n\n\n\n
  • Symbol<\/strong>: Declares a variable sym<\/code> with a unique symbol.<\/li>\n\n\n\n
  • Object<\/strong>: Declares a variable person<\/code> with properties.<\/li>\n<\/ul>\n\n\n\n
    <!DOCTYPE html>\n<html lang="en">\n<head>\n    <meta charset="UTF-8">\n    <meta name="viewport" content="width=device-width, initial-scale=1.0">\n    <title>JavaScript Data Types Example<\/title>\n<\/head>\n<body>\n    <script>\n        \/\/ Number\n        let age = 25;\n        console.log("Age:", age);\n\n        \/\/ String\n        let name = "Jane";\n        console.log("Name:", name);\n\n        \/\/ Boolean\n        let isStudent = true;\n        console.log("Is student:", isStudent);\n\n        \/\/ Undefined\n        let city;\n        console.log("City:", city);\n\n        \/\/ Null\n        let car = null;\n        console.log("Car:", car);\n\n        \/\/ Symbol\n        let sym = Symbol("unique");\n        console.log("Symbol:", sym);\n\n        \/\/ Object\n        let person = {\n            firstName: "Jane",\n            lastName: "Doe",\n            age: 25\n        };\n        console.log("Person:", person);\n    <\/script>\n<\/body>\n<\/html><\/pre><\/div>\n\n\n\n
    \"\"<\/figure>\n\n\n\n
    <\/p>\n\n\n\n
    JavaScript Labs<\/strong><\/h2>\n\n\n\n