includes

The includes function checks if an array or string contains a given value.

Syntax

includes<T>(array: T[] | string, value: T | string, fromIndex?: number): boolean;

Parameters

Name	Type	Description
array	T[] | string	Source array or string
value	T | string	Value to search for
fromIndex	number	Starting index for search (optional)

Returns

Type	Description
boolean	Returns true if the value is found

Examples

includes([1, 2, 3], 2); // => true
includes("abc", "b"); // => true
includes([1, 2, 3], 4); // => false

Notes

• Equivalent to the native Array.prototype.includes method.
• Useful for quick searches in arrays or strings.

References

• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes