2019-05-31 F2E workshop Day

Yahoo筆試

• js 的 == & === 的差別?

• Linked List 插入、刪除、搜尋的時間複雜度 插入 O(1) 刪除 O(1) 搜尋 O(n)

請寫出下面代碼的運行結果

1. async await setTimeout

    async function async1() {
        console.log('async1 start');
        await async2();
        console.log('async1 end');           
    }
    async function async2() {
        console.log('async2');
    }
    console.log('script start');
    setTimeout(function() {
        console.log('setTimeout');
    }, 0)
    async1();
    new Promise(function(resolve) {
        console.log('promise1');
        resolve();
    }).then(function() {
        console.log('promise2');
    });
    console.log('script end');
       
   

    //william yang's solution
    console.log('script start');
    console.log('async1 start');
    console.log('script end');
    console.log('promise1');
    console.log('setTimeout');
     console.log('async2');
    console.log('async1 end');   
    console.log('promise2');
       
    //
    script start
    async1 start
    async2
    promise1
    script end
    promise2
    setTimeout
    async1 end
       
   

2. Object ```javascript {.line-numbers} var a = {};b = {key:’b’};c = {key:’c’};a[b] = 123;a[c] = 456;console.log(a[b]);

    Solution
    ```javascript
    //console.log(a[b])
    456
   

3. setTimeout ```javascript {.line-numbers} console.log(“a”); setTimeout(()=>{ console.log(“b”) },0); while(1){}

    Solution
    ```javascript
    a