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48 lines
1.1 KiB
JavaScript
48 lines
1.1 KiB
JavaScript
var baseToString = require('../internal/baseToString');
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/* Native method references for those with the same name as other `lodash` methods. */
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var nativeFloor = Math.floor,
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nativeIsFinite = global.isFinite;
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/**
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* Repeats the given string `n` times.
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*
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* @static
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* @memberOf _
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* @category String
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* @param {string} [string=''] The string to repeat.
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* @param {number} [n=0] The number of times to repeat the string.
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* @returns {string} Returns the repeated string.
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* @example
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*
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* _.repeat('*', 3);
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* // => '***'
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*
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* _.repeat('abc', 2);
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* // => 'abcabc'
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*
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* _.repeat('abc', 0);
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* // => ''
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*/
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function repeat(string, n) {
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var result = '';
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string = baseToString(string);
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n = +n;
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if (n < 1 || !string || !nativeIsFinite(n)) {
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return result;
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}
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// Leverage the exponentiation by squaring algorithm for a faster repeat.
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// See https://en.wikipedia.org/wiki/Exponentiation_by_squaring for more details.
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do {
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if (n % 2) {
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result += string;
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}
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n = nativeFloor(n / 2);
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string += string;
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} while (n);
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return result;
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}
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module.exports = repeat;
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