sortedIndexOf
INFO
This function can only be imported from es-toolkit/compat for compatibility reasons. This is because there are native JavaScript APIs that can replace it, or it hasn't been sufficiently optimized yet.
When you import this function from es-toolkit/compat, it behaves exactly the same as lodash.
This function finds the index of the first occurrence of the second argument value in a sorted array. In other words, it tells you at which position the value you're looking for is located in the sorted array. It uses the sortedIndex function, repeatedly comparing and returning the index.
Interface
typescript
export function sortedIndexOf(array: ArrayLike | null | undefined, value: T): number;Parameters
array(ArrayLike | null | undefined): A sorted array. If the array is null or undefined, it returns -1.value(T): The value to search for in the sorted array through comparison.
Return Value
(number): The index at which the value should be inserted to maintain the sort order.
Examples
typescript
import { sortedIndexOf } from 'es-toolkit/compat';
const numbers = [11, 22, 33, 44, 55];
sortedIndexOf(numbers, 11); // Return value: 0
sortedIndexOf(numbers, 30); // Return value: -1
// If the value is duplicated, it returns the first index of the value.
const duplicateNumbers = [1, 2, 2, 3, 3, 3, 4];
sortedIndexOf(duplicateNumbers, 3); // Return value: 3
// If the array is unsorted, it can return the wrong index.
const unSortedArray = [55, 33, 22, 11, 44];
sortedIndexOf(unSortedArray, 11); // Return value: -1
// -0 and 0 are treated the same
const mixedZeroArray = [-0, 0];
sortedIndexOf(mixedZeroArray, 0); // Return value: 0
sortedIndexOf(mixedZeroArray, -0); // Return value: 0
// It works with array-like objects
const arrayLike = { length: 3, 0: 10, 1: 20, 2: 30 };
sortedIndexOf(arrayLike, 20); // Return value: 1