/**
 * Finds the index of the first item in an array that matches the given predicate function.
 *
 * @template T
 * @param {ArrayLike<T> | null | undefined} arr - The array to search through.
 * @param {(item: T, index: number, arr: T[]) => unknown} doesMatch - A function that takes an item, its index, and the array, and returns a truthy value if the item matches the criteria.
 * @param {number} [fromIndex=0] - The index to start the search from, defaults to 0.
 * @returns {number} - The index of the first item that matches the predicate, or `undefined` if no match is found.
 *
 * @example
 * // Using a predicate function
 * const items = [1, 2, 3, 4, 5];
 * const result = find(items, (item) => item > 3);
 * console.log(result); // 4
 */
declare function findIndex<T>(arr: ArrayLike<T> | null | undefined, doesMatch: (item: T, index: number, arr: readonly T[]) => unknown, fromIndex?: number): number;
/**
 * Finds the index of the first item in an array that matches the given partial object.
 *
 * @template T
 * @param {ArrayLike<T> | null | undefined} arr - The array to search through.
 * @param {Partial<T>} doesMatch - A partial object that specifies the properties to match.
 * @param {number} [fromIndex=0] - The index to start the search from, defaults to 0.
 * @returns {number} - The index of the first item that matches the partial object, or `undefined` if no match is found.
 *
 * @example
 * // Using a partial object
 * const items = [{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }];
 * const result = findIndex(items, { name: 'Bob' });
 * console.log(result); // 1
 */
declare function findIndex<T>(arr: ArrayLike<T> | null | undefined, doesMatch: Partial<T>, fromIndex?: number): number;
/**
 * Finds the index of the first item in an array that matches a property with a specific value.
 *
 * @template T
 * @param {ArrayLike<T> | null | undefined} arr - The array to search through.
 * @param {[keyof T, unknown]} doesMatchProperty - An array where the first element is the property key and the second element is the value to match.
 * @param {number} [fromIndex=0] - The index to start the search from, defaults to 0.
 * @returns {number} - The index of the first item that has the specified property value, or `undefined` if no match is found.
 *
 * @example
 * // Using a property-value pair
 * const items = [{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }];
 * const result = findIndex(items, ['name', 'Alice']);
 * console.log(result); // 0
 */
declare function findIndex<T>(arr: ArrayLike<T> | null | undefined, doesMatchProperty: [keyof T, unknown], fromIndex?: number): number;
/**
 * Finds the index of the first item in an array that has a specific property, where the property name is provided as a PropertyKey.
 *
 * @template T
 * @param {ArrayLike<T> | null | undefined} arr - The array to search through.
 * @param {PropertyKey} propertyToCheck - The property name to check.
 * @param {number} [fromIndex=0] - The index to start the search from, defaults to 0.
 * @returns {number} - The index of the first item that has the specified property, or `undefined` if no match is found.
 *
 * @example
 * // Using a property name
 * const items = [{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }];
 * const result = findIndex(items, 'name');
 * console.log(result); // 0
 */
declare function findIndex<T>(arr: ArrayLike<T> | null | undefined, propertyToCheck: PropertyKey, fromIndex?: number): number;

export { findIndex };
