JS代码阅读
//通过predicate函数判断过滤数组function filterArray(/*array*/a, /*boolean function*/ predicate) {var results = [];var length = a.length;// In case predicate changes the length!for(var i = 0; i < length; i++) {var element = a[i];if (predicate(element)) results.push(element);}return results;}//Retrun the array of values that reaults when each of the elements//Of the array a are passed to the function f//返回a数组的所有值经过f函数运算后的结果数组function mapArray(/*array*/a, /*function*/ f) {var r = [];// to hold the resultsvar length = a.length;// In case f changes the length!for(var i = 0; i < length; i++) r[i] = f(a[i]);return r;}//给o对象绑定函数，并调用function bindMethod(/*object*/o ,/*function*/ f) {return function() { return f.apply(o, arguments) }}//返回一个函数调用函数f,带有指定参数和任何额外的参数传递给函数function bindArguments(/*function*/f /*, initial arguments...*/) {var boundArgs = arguments;return function() {//Build up an array of arguments. It start with the previously//bound arguments and is extended with the arguments passed newvar args = [];for(var i= 1; i < boundArgs.length; i++) args.push(boundArgs[i]);for(var i= 0; i < arguments.length; i++) args.push(arguments[i]);//Now invoke the function with these argumentsreturn f.apply(this,args)}}//return an array that holds the names of the enumerable property of obj//返回一个数组保存姓名的枚举属性对象function getPropertyNames(/*object*/obj) {var r = [];for(name in obj) r.push(name);return r;}//Copy the enumerable properties of the object from to the object to.//if to in null, a new object is created. the function returns to or the//newly created object.//复制的可枚举属性的对象从对象。如果无效，一个新的对象被创建。该函数返回或者新创建的对象。function copyProperties(/*object*/ from, /*optional object*/ to) {if(!to) to = {};for(p in from) to[p] = from[p];return to;}//Copy the enumerable properties of the object from to the object to,//but only the ones that are not already defined by to.//This is useful, for example, when from contains default values that//we want to use if they are not already defined in to.//复制的可枚举属性的对象从对象，但只有那些没有已定义的。这是有用的，例如，当从包含默认值我们要使用如果他们没有已定义在。function copyUndefinedProperties(/*objecr*/ from, /*objecr*/ to) { for(p in from) { if(!p in to) to[p] = from[p]; }}