<meta http-equiv="Content-Security-Policy" content="script-src 'self'>
SRI Subresource Integrity
<script crossorigin="anonymous" integrity="sha256-xxxx" src="http://cdn.example.com/js/jquery.js"></script> function Name(name) {
this.name = name;
}
Name.prototype.getName = function() {
console.log(this.name);
}
function Person() {
Person.prototype = Object.create(Name.prototype) // 继承方法
Person.__proto__ = Name // 继承属性
Person.__proto__.apply(this, arguments) //super
} var array = [0, 1, 4, 6, 3, 0, 6];
function unique(obj) {
return obj.reduceRight(function(a, c, index, d) {
if (a == c || (f = d.lastIndexOf(c)) !== index)
d.splice(index || f, 1);
if (!index) return d
});
}
unique(array); // outputs: [0, 1, 4, 6, 3]
//others
function uniq(array) {
var n = 0;
var p = 0;
for (var i = 1; i < array.length;) {
if (array[i] === array[n]) {
array.splice(i, 1);
} else {
n++;
i++;
}
}
return array;
}
function uniq(array) {
for (var i = 0; i < array.length;) {
if ((c = array.lastIndexOf(array[i])) !== i) {
array.splice(c, 1)
} else {
i++
}
}
return array
} Array.apply(this, { length: 100 }).map(Function.call, fn) // fn .. Number .. function(i) { return i; }-- /i (忽略大小写)
-- /g (全文查找出现的所有匹配字符)
-- /m (多行查找)
<link href="style.css" rel="stylesheet"> <!--始终阻塞渲染-->
<link href="print.css" rel="stylesheet" media="print"> <!--打印内容时适用,或想重新安排布局、更改字体适用-->
<link href="other.css" rel="stylesheet" media="(min-width: 40em)"> <!--媒体查询符合条件时阻塞渲染-->- 处理 HTML 标记并构建 DOM 树。
- 处理 CSS 标记并构建 CSSOM 树。
- 将 DOM 与 CSSOM 合并成一个渲染树。
- 根据渲染树来布局，以计算每个节点的几何信息。
- 将各个节点绘制到屏幕上。
var taskList = breakBigTaskIntoMicroTasks(monsterTaskList);
requestAnimationFrame(processTaskList);
function processTaskList(taskStartTime) {
var taskFinishTime;
do {
// Assume the next task is pushed onto a stack.
var nextTask = taskList.pop();
// Process nextTask.
processTask(nextTask);
// Go again if there’s enough time to do the next task.
taskFinishTime = window.performance.now();
} while (taskFinishTime - taskStartTime < 3);
if (taskList.length > 0)
requestAnimationFrame(processTaskList);
}function currying(fn) {
var args = [];
return function() {
if (arguments.length === 0) {
return fn.apply(this, args);
}
console.log(1, arguments)
Array.prototype.push.apply(args, arguments)
return arguments.callee;
}
}
var pure = function() {
console.log(2, arguments);
if (arguments.length === 1) return arguments[0]
return Array.from(arguments).reduce((a, b) => a + b)
}
let a = currying(pure)
a(1)
a(2)()function sort(array) {
if (array.length <= 1) { return array; }
var v = array.splice(0, 1)[0]
var left = [], right = [];
for ( var i = 0; i < array.length; i++) {
if (array[i] < v) left.push(array[i])
else right.push(array[i])
}
console.log(left, right, array, v)
return sort(left).concat([v], sort(right))
}function traverse(obj, callback) {
var p = [];
function _traverse(_obj) {
if (typeof _obj && _obj.length) {
for (var j = 0; j < _obj.length; j++) {
_traverse(_obj[j])
}
} else {
p.push(_obj)
if (callback) callback(_obj)
}
}
_traverse(obj);
return p;
}function bfs(array) {
var result = [];
(function traverse(a) {
let t = []
for (var i = 0; i < a.length; i++) {
if (typeof a[i] === 'object') {
t = t.concat(a[i])
} else {
result.push(a[i])
}
}
if (t.length > 0) {
traverse(t)
}
return result
})(array)
return result
}const promise1 = Promise.resolve('test')
Promise.resolve(promise1).then(console.log) // output: test, not a promise object1. WebSocket
2. iframe http get
function _asyncToGenerator(fn) {
return new Promise((resolve, reject) => {
let gen = fn.apply(this, arguments)
function step(key, args) {
try {
var val = gen[key](args)
resolve(val.value)
} catch (e) {
reject(e)
return
}
if (val.done) {
resolve(val.value)
} else {
return Promise.resolve(val.value).then(function (value) {
step('next', value)
}, function (err) {
step('throw', err)
})
}
}
return step('next')
})
}// (a, b, c为arguments)
var _call = function (_thisobj, a, b, c) {
return Function(a, b, c)
}(Function.call).call(Number, a, b, c) // (a, b, c为arguments)// 通过第二个call，_thisobj = Number
var _call = function (_thisobj, a, b, c) {
return Number(a, b, c)
}Array.apply(this, { length: 100 }).map(function (_thisobj, a, b, c) {
return Number(a, b, c)
})
// output: 0, 1, 2, 3...function* gen(taskQueue) {
let i = 0
while(i < taskQueue.length) {
const nextTask = taskQueue[i]
yield nextTask()
i++
}
}
function timeSlice(taskQueue, duration) {
const startTime = performance.now()
const g = gen(taskQueue)
let res
do {
res = g.next()
} while (res.done !== true && performance.now() - startTime < duration)
}function* gen(taskQueue) {
while(taskQueue.length > 0) {
const nextTask = taskQueue.shift()
nextTask()
yield taskQueue
}
}
function timeSlice(taskQueue, duration) {
return new Promise((resolve) => {
const startTime = performance.now()
const g = gen(taskQueue)
let res
let overtime = false
do {
res = g.next()
overtime = performance.now() - startTime > duration
if (res.done || overtime) {
resolve(taskQueue)
}
} while (res.done !== true && !overtime)
})
}
// 创建100万次循环任务
const tasks = Array.from({ length: 100000 }).map(t => () => { console.log(performance.now()) })
function run(tasks) {
timeSlice(tasks, 15).then((restTasks) => restTasks.length > 0 && run(restTasks))
}
run(tasks)链表的节点包括指针和数据，Node节点的指针是指向下一个节点的地址，以JS举例
class Node {
data: Object
next: Node
}
class LinkedList {
public head: Node
insertBeforeIndex(node: Node, index: number) {
let n = 0
let previousNode = this.head
let currentNode = this.head
while (currentNode.next && n++ < index) {
previousNode = currentNode
currentNode = currentNode.next
}
node.next = currentNode
previousNode.next = node
}
getNodeByIndex() {
// implementation
}
}function getAllCombinations(data, k) {
const result = []
function loop(data, index = 0, tempoary = []) {
for (let i = 0; i < data.length - (k - 1 - index); i++) {
tempoary[index] = data[i]
if (index === k - 1) {
result.push([...tempoary])
}
if (index < k - 1) {
const nextIndex = index + 1
loop(data.slice(i + 1), nextIndex, tempoary)
if (nextIndex === k - 1) {
tempoary = []
}
}
}
}
loop(data, 0)
return result
}