Function findIndex

findIndex<const Ar extends readonly unknown[]>(
array: Ar,
predicate: (value: Ar[number], index: ArrayIndex<Ar>, arr: Ar) => boolean,
): -1 | ArrayIndex<Ar>
Finds the index of the first element that satisfies a predicate.
Type Parameters
- const Ar extends readonly unknown[]
Parameters
- array: Ar
- predicate: (value: Ar[number], index: ArrayIndex<Ar>, arr: Ar) => boolean
Returns -1 | ArrayIndex<Ar>
Example
```
const letters = ['a', 'b', 'c'];

const indexOfB = Arr.findIndex(letters, (letter) => letter === 'b');
// eslint-disable-next-line unicorn/prefer-array-index-of
const indexOfMissing = Arr.findIndex<string>((letter) => letter === 'z')(
  letters,
);

assert(indexOfB === 1);
assert(indexOfMissing === -1);
```
- Defined in src/array/impl/array-utils-search.mts:192
findIndex<E>(
predicate: (value: E, index: Uint32, arr: readonly E[]) => boolean,
): (array: readonly E[]) => -1 | Uint32
Finds the index of the first element that satisfies a predicate.
Type Parameters
- E
Parameters
- predicate: (value: E, index: Uint32, arr: readonly E[]) => boolean
Returns (array: readonly E[]) => -1 | Uint32
Example
```
const letters = ['a', 'b', 'c'];

const indexOfB = Arr.findIndex(letters, (letter) => letter === 'b');
// eslint-disable-next-line unicorn/prefer-array-index-of
const indexOfMissing = Arr.findIndex<string>((letter) => letter === 'z')(
  letters,
);

assert(indexOfB === 1);
assert(indexOfMissing === -1);
```
- Defined in src/array/impl/array-utils-search.mts:197