技術標籤：Codewarscodewars字串filterjsjavascript

題目：

In this Kata, you will be given two strings a and b and your task will be to return the characters that are not common in the two strings.
這道題目中，接收兩個字串a和b，目的是返回這兩個字串中不重複的字元。

例子

solve("xyab","xzca")  // "ybzc" 
solve("xyab"
 
,"xzca")  // "ybzc"
solve("xyabb","xzca") // "ybbzc"
solve("abcd","xyz")   // "abcdxyz"
solve("xxx","xzca")   // "zca"

解法一：

// 通過兩次for迴圈，用includes()去判斷
function solve(a,b){
    var result = '';
    for
 
(let i=0;i<a.length;i++){
        if(!(b.includes(a[i]))) result += a[i]
    }
    for(let i=0;i<b.length;i++){
        if(!(a.includes(b[i]))) result += b[i]
    }
    return result;
}

解法二：(Best Practices)

// ES6 提供了新的資料結構 Set。它類似於陣列，但是成員的值都是唯一的，沒有重複的值。
function solve(a,b) {
    let setA = new Set
 
(a);
    let setB = new Set(b);
    return [...(a+b)].filter(c => setA.has(c) ^ setB.has(c)).join("");
};

解法三：

// 通過將兩個字串合併，再用filter去過濾
function solve(a,b){
    return (a+b).split("").filter(c => !a.includes(c) || !b.includes(c)).join("");
};