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Java script Variables Its Types With Full Example
- JavaScript is a dynamically-typed language, which means that variable types are not explicitly declared, and they can change during the execution of a program. However, JavaScript has different data types that variables can hold. Here are some examples:
Numbers
javascript
let age = 25;
let temperature = 98.6;
Strings
javascript
let name = "John";
let message = 'Hello, World!'; Booleans
javascript
let isStudent = true;
let hasJob = false;
Arrays
javascript
let numbers = [1, 2, 3, 4, 5];
let fruits = ['apple', 'orange', 'banana'];
Objects
javascript
let person = {
firstName: 'John',
lastName: 'Doe',
age: 30,
isStudent: false
};
Undefined
javascript
let undefinedVariable;Null
javascript
let nullVariable = null;
Functions
javascript
function greet(name) {
return 'Hello, ' + name + '!';
}
let greeting = greet('Alice');
Remember that JavaScript is loosely typed, so a variable’s type can change during the program’s execution:
javascript
let x = 10; // x is a number
x = 'Hello'; // now x is a string
x = true; // now x is a boolean
- This flexibility allows for dynamic and expressive coding but requires careful attention to avoid unexpected behavior. If you’re using modern JavaScript (ES6 and later), you can also use const and let to declare variables. const is used for constants (values that shouldn’t be changed), and let is used for variables whose values can be reassigned.