'use strict';
var arr = ['Bart', 'Lisa', 'Adam'];


//for
for(var i=0;i<arr.length;i++){
    alert("Hello , "+arr[i]+" !");
}

for (var index in arr) {
  alert(`Hello, ${arr[index]}!`);
}

for (i = arr.length-1; i >= 0; i--){
  alert(`Hello, ${arr[i]}!`);
}

//while
var i=0;
while(i<arr.length){
    alert("Hello , "+arr[i]+" !");
    i++;
}

//do...while逆序
var i=arr.length-1;
do{
    alert("Hello , "+arr[i]+" !");
    i--;
}while(i>=0);