kephin

(function(){ var a = b = 3; })();
//此function等同於
(function(){
  var a = 3;
  b = 3;
})();

// 所以此IIFE執行完後，在function內宣告的變數a會立即被回收
a; // -> Error: not defined
// 但是沒有宣告b，所以b是window內的全域屬性

kephin

/*
請依據以下範本撰寫一個 MyFunc 函式：
function MyFunc() {
    // YOUR CODE HERE
}

撰寫完成後，必須可以正常執行以下程式碼：
var o = MyFunc();

o.get_a() // 回傳 undefined

kephin

/*
請完成以下 API 設計，讓你的程式可以執行以下程式碼，並且得到預期的結果。串接 add 的次數沒有上限，最後一個 API 是 result() 才會回傳結果。
$(1).add(2).add(3).add(99).result() === 105
$(1).add(2).add(3).result() === 6
*/

function $(baseNumber) {
  let total = baseNumber;
  const obj = {};
  obj.add = function(number) {

kephin

/*
請完成以下 function a() {} 函式的程式撰寫，讓你的程式可以執行以下程式碼，並且得到預期的結果。
※ 傳入數字的範圍只有 0 ~ 9，且回傳型別必須為 number
a(2)[0](3).run() === 203
a(2)[3](3).run() === 233
a(5)[8](2).run() === 582
a(9)[9](9).run() === 999
*/

function a(first) {

kephin

Question 1

Write a function that takes two arrays as input, each array contains a list of A-Z; Your program should return True if the 2nd array is a subset of 1st array, or False if not.

For example:

• isSubset([A,B,C,D,E], [A,E,D]) = true
• isSubset([A,B,C,D,E], [A,D,Z]) = false
• isSubset([A,D,E], [A,A,D,E]) = true

kephin

Question 2

What is the computational complexity of your answer in Question 1? Can you explain why?

• O(n^2)
• O(nlogn)
• O(n)
• O(logn)

Answer:

kephin

Question 3

Write a function that takes an array of integers as input. For each integer, output the next fibonacci number.

Fibonacci number of Fn is defined by:

Fn = Fn-1 + Fn-2

F1 = 1, F2 = 1

kephin

Question 4

Please explain what is the bug in the following Javascript function, and how to correct it.

function createArrayOfFunctions(y) {  
  var arr = [];  
  for (var i = 0; i < y; i++) {   
    arr[i] = function(x) {
      return x + i;

kephin

Tutorial: Designing a GraphQL API

This tutorial was created by Shopify for internal purposes. We've created a public version of it since we think it's useful to anyone creating a GraphQL API.

It's based on lessons learned from creating and evolving production schemas at Shopify over almost 3 years. The tutorial has evolved and will continue to change in the future so nothing is set in stone.

kephin

// Start a method chain that will throw an error:
// --> foo() [catches error]
// -----> bar() [catches / rethrows error]
// --------> baz() [throws error]

foo();

function foo() {
  try {
    bar();