indexOf
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.
Finds the index of the first occurrence of a value in an array.
This method is similar to Array.prototype.indexOf, but it also finds NaN values. It uses strict equality (===) to compare elements other than NaN.
Signature
typescript
function indexOf<T>(array: T[] | null | undefined, searchElement: T, fromIndex?: number): number;Parameters
array(T[] | null | undefined): The array to search.searchElement(T): The value to search for.fromIndex(number, optional): The index to start the search at.
Returns
(number): The index (zero-based) of the first occurrence of the value in the array, or -1 if the value is not found.
Example
typescript
const array = [1, 2, 3, NaN];
indexOf(array, 3); // => 2
indexOf(array, NaN); // => 3