第一阶段基础算法

1.字符串

问：

输入: "Let's take LeetCode contest"
输出: "s'teL ekat edoCteeL tsetnoc" 

使用jest测试并解答：

sum.js

 

function sum(str) {
    //变成数组
    const words = str.split(" ");
    const wordsReverse = words.map((word) => {
        return word.split("").reverse().join('');
    });
    return wordsReverse.join(" ");
}
module.exports = sum

 sum.test.js

const sum = require('./sum.js')
test("zhuyu", () => {
    expect(sum("Let's take LeetCode contest")).toBe("s'teL ekat edoCteeL tsetnoc");
})