has

The has function checks if an object has a (possibly nested) property specified by a path (string or array of strings).

Syntax

has<T>(obj: T, path: string | string[]): boolean

Parameters

Name	Type	Description
obj	T	Source object.
path	string | string[]	Path to the property (e.g., "a.b.c" or ["a", "b", "c"]).

Return

Type	Description
boolean	Returns true if the property exists, otherwise false.

Examples

const obj = { a: { b: { c: 42 } } };
has(obj, 'a.b.c'); // true
has(obj, ['a', 'b', 'c']); // true
has(obj, 'a.b.x'); // false

Notes

• Supports paths with array notation (e.g., "a.b[0].c").
• Useful for validating the existence of nested properties.

References

• MDN: Object.hasOwn()