介绍

给定一串单词或短语，计算元音字母的数量。

实现

JavaScript

/**
 * @function countVowels
 * @description Given a string of words or phrases, count the number of vowels（元音）.
 * @param {String} str - The input string
 * @return {Number} - The number of vowels
 * @example countVowels("ABCDE") => 2
 * @example countVowels("Hello") => 2
 */

const countVowels = (str) => {
 if (typeof str !== "string") {
  throw new TypeError("Input should be a string");
 }

 const vowelRegex = /[aeiou]/gi;
 const vowelsArray = str.match(vowelRegex) || [];

 return vowelsArray.length;
};