39 lines
1.2 KiB
JavaScript
39 lines
1.2 KiB
JavaScript
//#region src/array/maxBy.ts
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/**
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* Finds the element in an array that has the maximum value when applying
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* the `getValue` function to each element.
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*
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* @template T - The type of elements in the array.
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* @param {T[]} items The array of elements to search.
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* @param {(element: T, index: number, array: readonly T[]) => number} getValue A function that selects a numeric value from each element.
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* @returns {T | undefined} The element with the maximum value as determined by the `getValue` function,
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* or `undefined` if the array is empty.
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* @example
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* maxBy([{ a: 1 }, { a: 2 }, { a: 3 }], x => x.a); // Returns: { a: 3 }
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* maxBy([], x => x.a); // Returns: undefined
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* maxBy(
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* [
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* { name: 'john', age: 30 },
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* { name: 'jane', age: 28 },
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* { name: 'joe', age: 26 },
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* ],
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* x => x.age
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* ); // Returns: { name: 'john', age: 30 }
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*/
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function maxBy(items, getValue) {
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if (items.length === 0) return;
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let maxElement = items[0];
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let max = getValue(maxElement, 0, items);
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for (let i = 1; i < items.length; i++) {
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const element = items[i];
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const value = getValue(element, i, items);
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if (value > max) {
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max = value;
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maxElement = element;
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}
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}
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return maxElement;
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}
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//#endregion
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export { maxBy };
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