JavaScript Function Types
JavaScript functions can be categorized based on their use of arguments and return values. Here are some common types:
1. Function Without Arguments
A function without arguments does not take any parameters.
// Function Without Arguments
function sayHello() {
console.log("Hello, World!");
}
// Calling the function
sayHello(); // Output: Hello, World!
2. Function With Arguments
A function with arguments takes one or more parameters.
// Function With Arguments
function greet(name) {
console.log("Hello, " + name + "!");
}
// Calling the function
greet("Alice"); // Output: Hello, Alice!
3. Function With Return Value
A function with a return value returns a result using the return keyword.
// Function With Return Value
function add(a, b) {
return a + b;
}
// Calling the function
var sum = add(5, 3);
console.log(sum); // Output: 8
4. Function With Arguments and Return Value
A function can take arguments and also return a value.
// Function With Arguments and Return Value
function multiply(a, b) {
return a * b;
}
// Calling the function
var product = multiply(4, 7);
console.log(product); // Output: 28
All in one Example (HTML file):
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Different types of functions in JavaScript</title>
</head>
<body>
<button onclick="message1();">Show message1</button>
<button onclick="message2('John Doe');">Show message2</button>
<button onclick="message3('John Doe','New York');">Show message3</button>
<button onclick="getresult();">Result1</button>
<button onclick="getresult2(8,3);">Result2</button>
<script src="funtypes.js"></script>
</body>
</html>
JavaScript file:
//Types of Functions
//1. Functions without arguments and without return values
function message1(){
window.alert("Hello world");
}
//2. Functions with arguments and without return values
function message2(name){
window.alert("Hello "+name+", How are you?");
}
//Multiple arguments
function message3(name,place){
window.alert("Hello I am "+name+", I am from "+place);
}
//3. Functions without arguments and with return values
function sum(){
var x=10;
var y=5;
var sum=x+y;
return sum;
}
function difference(){
var x=10;
var y=5;
var dif=x-y;
return dif;
}
function getresult(){
var s = sum();
var d = difference();
window.alert("Sum = "+s+" and Difference = "+d);
}
//4. Functions with arguments and return values
function sum2(x,y){
var sum=x+y;
return sum;
}
function difference2(x,y){
var dif=x-y;
return dif;
}
function getresult2(a,b){
var s = sum2(a,b);
var d = difference2(a,b);
window.alert("Sum = "+s+" and Difference = "+d);
}