33 lines
1.1 KiB
TypeScript
33 lines
1.1 KiB
TypeScript
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//#region src/compat/array/head.d.ts
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/**
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* Returns the first element of an array or `undefined` if the array is empty.
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*
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* @template T - The type of elements in the array.
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* @param {readonly [T, ...unknown[]]} array - A non-empty tuple with at least one element.
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* @returns {T} The first element of the array.
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*
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* @example
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* const arr = [1, 2, 3] as const;
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* const first = head(arr);
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* // first will be 1
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*/
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declare function head<T>(array: readonly [T, ...unknown[]]): T;
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/**
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* Returns the first element of an array or `undefined` if the array is empty.
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*
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* @template T - The type of elements in the array.
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* @param {ArrayLike<T> | null | undefined} array - The array from which to get the first element.
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* @returns {T | undefined} The first element of the array, or `undefined` if the array is empty/null/undefined.
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*
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* @example
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* const arr = [1, 2, 3];
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* const first = head(arr);
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* // first will be 1
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*
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* const emptyArr: number[] = [];
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* const noElement = head(emptyArr);
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* // noElement will be undefined
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*/
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declare function head<T>(array: ArrayLike<T> | null | undefined): T | undefined;
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//#endregion
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export { head };
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