FreeCodeCamp：Confirm the Ending

要求：

检查一个字符串(str)是否以指定的字符串(target)结尾。

如果是，返回true;如果不是，返回false。

结果：

• confirmEnding("Bastian", "n") 应该返回 true.

• confirmEnding("Connor", "n") 应该返回 false.

• confirmEnding("Walking on water and developing software from a specification are easy if both are frozen", "specification") 应该返回 false.

• confirmEnding("He has to give me a new name", "name") 应该返回 true.

• confirmEnding("He has to give me a new name", "me") 应该返回 true.

• confirmEnding("He has to give me a new name", "na") 应该返回 false.

• confirmEnding("If you want to save our world, you must hurry. We dont know how much longer we can withstand the nothing", "mountain") 应该返回 false.

 1 function confirmEnding(str, target) {
 2   // "Never give up and good luck will find you."
 3   var length=target.length;
 4   var strlength=str.length;
 5   var newstr=str.substr(strlength-length,length);
 6   if(newstr==target){
 7     return true;
 8   }
 9   else{
10     return false;
11   }
12   // -- Falcor
13   //return str;
14 }
15
16 confirmEnding("Bastian", "n");