Front End engineer Face question JavaScript section (fifth quarter)

Alert (' 1 ' + 1)//11, not 2, this easy to forget

The second question, it's all basic, it's easy to fall out of the pit.

(function() {     var a = b = 6;}) () Console.log (b); // 6 global variable declaration

In advance of the third question statement

function Test () {  console.log (a);  Console.log (foo ());   var a = 1;   function foo () {     return 2;  }} test ();

This is simple.

var fullname = ' John Doe '; var obj = {  ' Colin ihrig ',  prop: {     ' Aurelio De Rosa ',       function() {        returnthis. FullName;}}  } Console.log (Obj.prop.getFullname ()); var test = obj.prop.getfullname;console.log (Test ())'

Next, the handwriting event agent

functiondelegateevent (Interfaceele, selector, type, fn) {if(Interfaceele.addeventlistener) {Interfaceele.addeventlistener (TYPE,EVENTFN,false); }      Else{Interfaceele.attach (' On ' +TYPE,EVETNFN); }    functionEVENTFN (e) {varE = e| |window.event; vartarget = E.target | |e.srcelement; if(Matchselecter (Target,selector)) {//whether a is a          if(FN) {fn.call (target,e); }     }   }}functionMathcselector (ele,selector) {if(Selector.charat (0) = = = ' # '){      returnEle.id = = Selector.slice (1); }   if(Selector.charat (0) = = '. '){      return("+ ele.classname+". IndexOf ("+ selector.slice (1) +")! =-1)    returnEle.targetName.toLowerCase () = = =slector.tolowercase (); }}varOdiv = Docyment.getelementbyid ("Odiv");d elegateevent (Odiv,' A ', ' click ',function() {alert (1)})

Front End engineer Face question JavaScript section (fifth quarter)