freeCodeCamp Confirm the Ending

 1 function confirmEnding(str, target) {
 2 
 3   // 获取字符串和所要匹配的字符串参数的长度
 4 
 5   var strlength=str.length;
 6   var targetlength=target.length;
 7 
 8    // 截取所要匹配的区域
 9 
10   var result=str.substr(strlength-targetlength,strlength-1);
11   if(result==target)
12     {
13       return true;
14     }
15   else
16     {
17       return false;
18     }
19    
20 
21 }
22 
23 confirmEnding("Bastian", "n");

true