hasIn

INFO

This function is only available in es-toolkit/compat for compatibility reasons. It either has alternative native JavaScript APIs or isn't fully optimized yet.

When imported from es-toolkit/compat, it behaves exactly like lodash and provides the same functionalities, as detailed here.

Checks if a given path exists in an object, including inherited properties.

You can provide the path as a single property key, an array of property keys, or a string representing a deep path.

Unlike has, which only checks for own properties, hasIn also checks for properties in the prototype chain.

If the path is an index and the object is an array or an arguments object, the function will verify if the index is valid and within the bounds of the array or arguments object, even if the array or arguments object is sparse (i.e., not all indexes are defined).

Signature

function hasIn(object: unknown, path: string | number | symbol | Array<string | number | symbol>): boolean;

Parameters

• object (unknown): The object to query.
• path (string or number or symbol or Array<string | number | symbol>): The path to check. This can be a single property key, an array of property keys, or a string representing a deep path.

Returns

(boolean): Returns true if the path exists (own or inherited) in the object, false otherwise.

Examples

import { has, hasIn } from 'es-toolkit/compat';

const obj = { a: { b: { c: 3 } } };

hasIn(obj, 'a'); // true
hasIn(obj, ['a', 'b']); // true
hasIn(obj, ['a', 'b', 'c']); // true
hasIn(obj, 'a.b.c'); // true
hasIn(obj, 'a.b.d'); // false
hasIn(obj, ['a', 'b', 'c', 'd']); // false

// Example with inherited properties:
function Rectangle() {}
Rectangle.prototype.area = function () {};

const rect = new Rectangle();
hasIn(rect, 'area'); // true - hasIn checks both own and inherited properties
has(rect, 'area'); // false - has only checks own properties

Demo

import "./styles.css";

document.getElementById("app").innerHTML = `
<h1>Hello world</h1>
`;

Open Sandbox