JavaScript: function Operator

Last update on May 28 2022 10:33:40 (UTC/GMT +8 hours)

Description

The function operator defines a function inside an expression.

Version

Implemented in JavaScript 1.5

Syntax

var1 = function( parameter1, parameter2,......parametern)
{
statement(s)
}

Parameters

parameters: A list of arguments to the function.

statement(s): JavaScript statements.

Example:

The following web document demonstrates the use of function operator. It sets x to a function that returns the square of two numbers.

HTML Code

<!doctype html>
<head>
<meta charset="utf-8">
<title>JavaScript function operator example.</title>
;meta name="description" content="This document contains an example of JavaScript function operator "/>
</head>
<script src="javascript-function-operator-example1.js"></script>
</body>
</html>

JS Code


var a = 12;
var b = 14;
var x = function(a,b)
{
return a*a+2*a*b+b*b;
};
console.log("The square of "+a+ " and "+b +" is " +x(a,b));

View the example in the browser

Practice the example online

See the Pen function-1 by w3resource (@w3resource) on CodePen.

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JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = [];
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

console.log(arr.join());
arr.splice(2, 0, "Lene");
console.log(arr.join());

Ref: https://bit.ly/2BXbp04