27 lines
717 B
JavaScript
27 lines
717 B
JavaScript
import toDate from "../toDate/index.js";
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import requiredArgs from "../_lib/requiredArgs/index.js";
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/**
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* @name getDecade
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* @category Decade Helpers
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* @summary Get the decade of the given date.
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*
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* @description
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* Get the decade of the given date.
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*
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* @param {Date|Number} date - the given date
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* @returns {Number} the year of decade
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* @throws {TypeError} 1 argument required
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*
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* @example
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* // Which decade belongs 27 November 1942?
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* const result = getDecade(new Date(1942, 10, 27))
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* //=> 1940
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*/
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export default function getDecade(dirtyDate) {
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requiredArgs(1, arguments);
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var date = toDate(dirtyDate);
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var year = date.getFullYear();
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var decade = Math.floor(year / 10) * 10;
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return decade;
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} |