functionMyString(str){vararr=str.split('');arr.toString=function(){returnarr.join('');}arr.valueOf=function(){returnarr.toString();}arr.charAt=function(index){returnarr[parseInt(index)];}arr.concat=function(conStr){returnstr+conStr;}arr.slice=function(start,end){if(end<0){end=arr.length-1;}varsubstring='';for(vari=0;iif(i>=start&&isubstring+=arr[i];}}returnsubstring;}arr.split=function(splitStr){varsplitArr=[];vari,j,start;for(i=0,start=i;ifor(j=0;jif(arr[i+j]!=splitStr[j])break;}if(j==splitStr.length){varsubstring=arr.slice(start,i);splitArr.push(substring);start=(i+j);}}if(startvarsubstring=arr.slice(start,i);splitArr.push(substring);}returnsplitArr;}arr.reverse=function(){for(vari=0,j=arr.length-1;ivartp=arr[i];arr[i]=arr[j];arr[j]=tp;}returnarr;}returnarr;}varstring=newMyString('hello');console.log(string.length);console.log(string[0]);console.log(string.charAt(1));console.log(string.charAt('2'));console.log(string.charAt('e'));varconStr=string.concat('world');console.log(conStr);varsliceStr=string.slice(1,3);console.log(sliceStr);sliceStr=string.slice(0,-1);console.log(sliceStr);console.log(string.split('e'));console.log(string.split('l'));//string.reverse();console.log(string.reverse().toString());