Jul 8, 2025 · The instanceof operator tests to see if the prototype property of a constructor appears anywhere in the prototype chain of an object. The return value is a boolean value. Its behavior can …

The instanceof operator returns true if an object is an instance of a specified object: instanceof is an ECMAScript3 (JavaScript 1999) feature. It is supported in all browsers: The spread (...) Operator.

Checks the current object and returns true if the object is of the specified object type. Here are some good examples and here is an example taken directly from Mozilla's developer site: One thing worth …

Sep 26, 2025 · The instanceof operator allows to check whether an object belongs to a certain class. It also takes inheritance into account. Such a check may be necessary in many cases. For example, it …

In this tutorial, you'll learn how to use the JavaScript instanceof operator to determine if a constructor's prototype appears in the prototype chain of an object.

Jul 11, 2025 · The instanceof operator in JavaScript is used to check the type of an object at run time. It returns a boolean value if true then it indicates that the object is an instance of a particular class and …

Understand how JavaScript’s instanceof operator works, when to use it, and why it matters for safe object type checking across complex applications.

2 days ago · Starting with the basics instanceof is a binary operator used in JavaScript to check whether an object is an instance of a particular class or constructor function.

Jan 7, 2026 · In JavaScript, understanding object types and their relationships is fundamental to writing robust code. One tool that helps with this is the instanceof operator, which checks if an object is an …

The instanceof operator in JavaScript is a powerful tool for determining whether an object is an instance of a specific class or constructor function. It assists developers in verifying the type of an object at …