//正则
function confirmEnding(str, target) {  
  return new RegExp(`${target}$`).test(str);//  /target$/ ,这种写正则的方式是不能用变量的
}
confirmEnding("Bastian", "n");

//str.endswith()
function confirmEnding(str, target) {
  return str.endsWith(target)
}
confirmEnding("Bastian", "n");

//for
function confirmEnding(str, target) {
  for(let i= 0; i< target.length; i++){
    if(str[str.length-1-i] !== target[target.length-1-i]){
      return false;
    }
  }
  return true;
}
confirmEnding("Bastian", "n");

//substring
function confirmEnding(str, target) {
	//str.slice() 只有一个参数时，是从这个下标一直截取到最后
  return str.slice(str.length - target.length) === target;
}
confirmEnding("He has to give me a new name", "name");