How to Determine Object Class in JavaScript?

Determining Object Class in JavaScript

Unlike Java's .getClass() method, JavaScript does not have an exact equivalent due to its prototype-based nature. However, depending on the desired functionality, there are various alternatives to achieve similar results.

Options:

• typeof: Returns a string indicating the data type of the object, e.g., "function" for a function, "object" for a generic object.
• instanceof: Checks if an object is an instance of a specific class or its derived classes.
• obj.constructor: Accesses the constructor function that created the object, which often provides class information.
• func.prototype, proto.isPrototypeOf: Determine if an object was created from a specific class by comparing prototypes.

Examples:

function Foo() {}
var foo = new Foo();

typeof Foo;             // "function"
typeof foo;             // "object"
foo instanceof Foo;     // true
foo.constructor.name;   // "Foo"
Foo.prototype.isPrototypeOf(foo);   // true

Note: When using Uglify for code optimization, global class names may be altered. To prevent this, set the --mangle parameter to false in gulp or grunt.

The above is the detailed content of How to Determine Object Class in JavaScript?. For more information, please follow other related articles on the PHP Chinese website!