使用Substring（）和Substr（）来处理两个字符串

Question

假设我们必须使用Substring（）和/或Substr（）或两个字符串方法对字符串var first = "hi my name is this";和var second = "this";进行检查，以查看第二个字符串是否与第一个字符串的结尾匹配（我知道String.prototype.endsWith（））。怎么办？感谢

到目前为止，我有这个，但错了

function confirmEnding(str, target) {
  // calculate the length of second string
  // remove the end of the first string (same amount) with the first string
  //compare the two
  var secondStringLen = target.length;
  var firstStringLen = str.length;
  var firstStringEnding = str.substring(secondStringLen+1, -1);

  return firstStringEnding;
}

confirmEnding("abcaqwexefg", "efg");

Answer 1

你可以这样试试！

＆＃13;

＆＃13;

var first = "hi my name is this";
var second = "this";

function confirmEnding(str1, str2) {
  var l1 = str1.length,
    l2 = str2.length;

  var str = str1.substring(l1 - l2);

  if (str == str2)
    return true;
  else
    return false;
}

console.log(confirmEnding("abcaqwexefg", "efg"));
console.log(confirmEnding(first, second));

＆＃13;

＆＃13;

＆＃13;