<!DOCTYPE html>
<head>
<meta charset="utf-8"/>
<title> </title>
<script>
function getIndex(){
//1,声明一个数组,
var arr = ["no","zuo","no","die"];
//2,声明一个索引的变量,用于保存找到的数据的索引,默认值为负数
var index = -1;
//3,要求用户输入一个数据
var str = prompt("请输入一个数据","");
//4,循环查找,如果找到了就跳出循环
for(var i=0;i<arr.length;i++){
if(str == arr[i]){
index = i;
break;
}
}
//5,输出结果
if(index == -1){
console.log("没找到");
}else{
console.log(arr);
console.log(arr+"出现的索引为:"+index);
}
}
</script>
</head>
<body>
<button οnclick="getIndex()">查询某个</button>
</body>
</html>
用谷歌浏览器进行调试,F12,或者点击开发者工具,具体如下:
<img src="https://img-blog.youkuaiyun.com/20160301231153671?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />