关键词：
// apply 的模拟实现
Function.prototype.apply = function(context, arr)
var context = Object(context) || window;
context.fn = this;
var result;
if (!arr)
result = context.fn();
else
var args = [];
for (var i = 0, len = arr.length; i < len; i++)
args.push("arr[" + i + "]");
result = eval("context.fn(" + args + ")");
delete context.fn;
return result;
;
// call 的模拟实现
Function.prototype.call2 = function(context)
var context = context || window;
context.fn = this;
var args = [];
for (var i = 1, len = arguments.length; i < len; i++)
args.push("arguments[" + i + "]");
var result = eval("context.fn(" + args + ")");
delete context.fn;
return result;
;
// 测试一下
var value = 2;
var obj =
value: 1
;
function bar(name, age)
console.log(this.value);
return
value: this.value,
name: name,
age: age
;
bar.call(null); // 2
console.log(bar.call2(obj, "kevin", 18));
// 1
// Object
// value: 1,
// name: 'kevin',
// age: 18
//
// bind 的模拟实现
Function.prototype.bind2 = function(context)
if (typeof this !== "function")
throw new Error(
"Function.prototype.bind - what is trying to be bound is not callable"
);
var self = this;
var args = Array.prototype.slice.call(arguments, 1);
var fNOP = function() ;
var fBound = function()
var bindArgs = Array.prototype.slice.call(arguments);
return self.apply(
this instanceof fNOP ? this : context,
args.concat(bindArgs)
);
;
fNOP.prototype = this.prototype;
fBound.prototype = new fNOP();
return fBound;
;
// new 的模拟实现
function objectFactory()
var obj = new Object(),
Constructor = [].shift.call(arguments);
obj.__proto__ = Constructor.prototype;
var ret = Constructor.apply(obj, arguments);
return typeof ret === "object" ? ret : obj;
// 利用发布订阅模式，实现一个简单的数据绑定
function DataBinder(object_id)
// Create a simple PubSub object
var pubSub =
callbacks: ,
on: function(msg, callback)
this.callbacks[msg] = this.callbacks[msg] || [];
this.callbacks[msg].push(callback);
,
publish: function(msg)
this.callbacks[msg] = this.callbacks[msg] || [];
for (var i = 0, len = this.callbacks[msg].length; i <= len; i++)
this.callbacks[msg][i].apply(this, arguments);
,
data_attr = "data-bind-" + object_id,
message = object_id + ":change",
changeHandler = function(evt)
var target = evt.target || evt.srcElement, // IE8 compatibility
prop_name = target.getAttribute(data_attr);
if (prop_name && prop_name !== "")
pubSub.publish(message, prop_name, target.value);
;
// Listen to change events and proxy to PubSub
if (document.addEventListener)
document.addEventListener("change", changeHandler, false);
else
// IE8 uses attachEvent instead of addEventListener
document.attachEvent("onchange", changeHandler);
// PubSub propagates changes to all bound elements
pubSub.on(message, function(evt, prop_name, new_val)
var elements = document.querySelectorAll("[" + data_attr + "=" + prop_name + "]"),
tag_name;
for (var i = 0, len = elements.length; i <= len; i++)
tag_name = elements[i].tagName.toLowerCase();
if (tag_name === "input" || tag_name === "textarea" || tag_name === "select")
elements[i].value = new_val;
else
elements[i].innerHTML = new_val;
);
return pubSub;
function Node(element)
this.element = element;
this.next = null;
function LinkedList()
this._head = new Node("This is Head Node.");
this._size = 0;
LinkedList.prototype.display = function()
var currNode = this.getHead().next;
while (currNode)
console.log(currNode.element);
currNode = currNode.next;
;
LinkedList.prototype.remove = function(item)
if (item)
var preNode = this.findPre(item);
if (preNode == null) return;
if (preNode.next !== null)
preNode.next = preNode.next.next;
this._size--;
;
LinkedList.prototype.add = function(item)
this.insert(item);
;
LinkedList.prototype.insert = function(newElement, item)
var newNode = new Node(newElement);
var finder = item ? this.find(item) : null;
if (!finder)
var last = this.findLast();
last.next = newNode;
else
newNode.next = finder.next;
finder.next = newNode;
this._size++;
;
/*********************** Utility Functions ********************************/
LinkedList.prototype.findLast = function()
var currNode = this.getHead();
while (currNode.next)
currNode = currNode.next;
return currNode;
;
LinkedList.prototype.findPre = function(item)
var currNode = this.getHead();
while (currNode.next !== null && currNode.next.element !== item)
currNode = currNode.next;
return currNode;
;
LinkedList.prototype.find = function(item)
if (item == null) return null;
var currNode = this.getHead();
while (currNode && currNode.element !== item)
currNode = currNode.next;
return currNode;
;
var attributions =
function get(that, key)
return attributions[that] && attributions[that][key]
function set(that, key, value)
if(!attributions[that]) attributions[that] =
attributions[that][key] = value
class MyClass
set()
set.apply(this, 'name', "cpf")
get()
let name = get.apply(this, 'name')
console.log(name)
var events =
var data =
class MyClass
on(event, handler)
if(!events[event]) events[event] = []
events[event].push(handler)
trigger(event, params = [])
let evts = events[event]
if(Array.isArray(evts)) evts.forEach(callback =>
if(typeof callback === 'function')
if(Array.isArray(params)) callback.apply(this, params)
else callback.call(this, params)
)
get(key)
return data[this] && data[this][key]
set(key, value, notify = true)
if(!data[this]) data[this] =
data[this][key] = value
if(notify)
this.trigger('change:' + key, value)
call(factory, ...args)
factory.apply(this, args)
debounce = (fn, delay) =>
let timer;
return () =>
clearTimeout(timer)
timer = setTimeout(() =>
fn.apply(this, arguments)
, delay);
throttle = (fn, threshhold = 250) =>
let last
let timer
return ()=>
let now = +new Date()
if (last && now < last + threshhold)
clearTimeout(timer)
timer = setTimeout(() =>
last = now
fn.apply(this, arguments)
, threshhold);
else
last = now
fn.apply(context, args)
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