ts-extras/distribution/array-first.d.ts

Essential utilities for TypeScript projects

/**
Return the first item of an array with stronger typing for tuples.

This mirrors getting `array[0]` but with better type safety and handling for empty arrays.

@example
```
import {arrayFirst} from 'ts-extras';

const tuple = ['abc', 123, true] as const;
const first = arrayFirst(tuple);
//=> 'abc'
//   ^? 'abc'

const array = ['a', 'b', 'c'];
const maybeFirst = arrayFirst(array);
//=> 'a'
//   ^? string | undefined

// Empty arrays
const empty: string[] = [];
const noFirst = arrayFirst(empty);
//=> undefined
//   ^? string | undefined
```

@category Improved builtin
*/
export declare function arrayFirst<const ArrayType extends readonly [unknown, ...unknown[]]>(array: ArrayType): ArrayType[0];
export declare function arrayFirst<ArrayType extends readonly unknown[]>(array: ArrayType): ArrayType[number] | undefined;