1.每個單詞手字母大寫

var capitalizeEveryWord = str => str.replace(/\b[a-z]/g, char => char.toUpperCase());
capitalizeEveryWord(‘hello world‘);

2.計算平均數

var calculatedMean = arr => arr.reduce((total, number) => total + number, 0) / arr.length;
calculatedMean([1, 2, 3])

3.駝峰命名

const camelCase = str => str.replace(/-(\w)/g, (char1, char2) => char2.toUpperCase());
console.log(camelCase(
 
‘hello-world‘));

4.計算數字在數組中出現次數

const numberOfReplications = (arr, num) => arr.reduce((m, n) => num == n ? m+1 : m+0, 0);
numberOfReplications([1, 2, 3, 1], 1);

5.解析URL參數

const getQueryString = (name) =>{
     const reg = new RegExp("(^|&)"+ name +"=([^&]*)(&|$)");
     const r 
 
= window.location.search.substr(1).match(reg);
     if(r) return  decodeURI(r[2]); 
    return null;
}

6.求數組中最大值

const maximum = arr => Math.max(...arr);
maximum([1,2,10]);

7.求數組中最小值

const minimum = arr => Math.min(...arr);
 minimum([1,2,3,4]);

請大家多多指出不足。。。

js常見算法（一）