Solve the JavaScript problem of Uncle Tom

Original reference, http://www.cnblogs.com/TomXu/archive/2012/02/10/2342098.html

Uncle Tom's Blog in-depth understanding of the JavaScript series is really our guiding beacon to learn JavaScript, http://www.cnblogs.com/TomXu/archive/2011/12/15/2288411.html

Friends who are interested to learn it by themselves. The answer to his question is 6.

First question: Find the largest element in a numeric array (using the Match.max function)

The original answer is this.

functionGetmax (Array) {
    var max= array[0];
Array.ForEach (function (Element) {
Max<element?max=element:max;
})  return max; 
} 
 var arr = [12, 5 8, 130 44,99,888]; 
 console. Log (getmax (arr))  
    

See the hint, check the Match.max document Https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Math/max

Find out that it's just as it should be.

 var arr = [12, 5 8, 130 44,99,888]; 
 console. Log (math. Max. apply (null             

In fact, this question is the use of the test and the usual multi-API documentation is familiar. It should be very simple to be familiar.

The second question: converts a numeric array into a function array (each function pops up the corresponding number)

functionnumbertofunction (arr) {varFunarr = [];    Arr.foreach (convert); functionConvert (element,index,array) {functionlog (Element) {return function() {console.log (element);};    } funarr.push (log (element)); }    returnFunarr;}vararr = [12, 5, 8, 130, 44,99,888];varFuna =numbertofunction (arr);//validation result Funa.foreach (function(elment) {Elment.call ();});

I understand this problem is the concept of closures, that is, closures. There are two points to note

1. The loop cannot use closures so a function convert is created.

2. If you want to accept the parameter element of convert in push, you cannot use closures. All add function log again. Otherwise, you can create a function array, but the result is not printed in the array.

question three: sort an object array (sorting criteria is the number of attributes per element object)

varPersons =[{name:' Jason ', Age:20, Gender:' Male '}, {name:' Tom ', Age:18}, {name:' May ', Age:18, Gender:' Female ', High:' 165cm '}];p Ersons.sort (function(A, b) {if(Object.getownpropertynames (a). length >Object.getownpropertynames (b). Length) {        return1; }    if(Object.getownpropertynames (a) .length<Object.getownpropertynames (b). Length) {        return-1; }    return0;}); Console.log (persons);

Object.keys (). Length can also. Test API Common Sense Array.Sort,object.getownpropertynames() or Object.keys ()

question fourth: print out Fibonacci with JavaScript (no global variables)

 function   Pfibonacci () { var  arrfib = [0,1 var  count = arguments[0]?arguments[0]:10     return   {print:  function   0 1 for  (var  i = 2; i< count;i++< Span style= "color: #000000;"                ) {Arrfib[i]  = arrfib[i-1] + arrfib[i-2). print (); 

Question Fifth: The function of implementing the following syntax: var a = (5). Plus (3). Minus (6);

function (x) {    return this +function(x) {    Console.log (  This );     return  this- x;};

Console.log ((5). Plus (3). Minus (6)); 2

Test the use of prototype.

Span style= "font-size:15px;" > sixth: The ability to implement the following syntax: var a = Add (2) (3) (4);//9

var function () {    var x = arguments[0];     return function () {        + = arguments[0]        ; return function () {            return x + = Arguments[0];}};    };
Console.log (Add (2) (3) (4));//9

This problem is very tangled, want to write an Add () () () (...), the infinite method fails. can only be fixed 3 heavy connected.

Solve the JavaScript problem of Uncle Tom