w3resource
JavaScript Operators

JavaScript: in Operator

Description

The in operator is used to check whether a given property is available on an object.

Syntax

property in object

Parameters

property: Name of the property.

object: Name of the object.

Example:

The following web document shows how the in operator is used.

HTML Code

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

JS Code

var employeeobj = {name:"Robert",designation:"Officer",age:"34"};
if ("designation" in employeeobj)
{
console.log('Designation property is present'); 
}
else
{
console.log('Designation property is not present'); 
}

View the example in the browser

Practice the example online

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


See also

Conditional Operator
comma
delete
function
instanceof
new
this
typeof
void



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