<script>
window.onload = function (){
var aBtn = document.getElementsByTagName('input');
var aP = document.getElementsByTagName('p');
// 想建立“匹配”“对应”关系，就用索引值
var arr = [ '莫涛', '张森', '杜鹏' ];
for( var i=0; i<aBtn.length; i++ ){
aBtn[i].index = i; // 自定义属性（索引值）
aBtn[i].onclick = function (){
// alert( arr[ this.index ] );
this.value = arr[ this.index ];
aP[ this.index ].innerHTML = arr[ this.index ];
};
}
};
</script>
</head>
<body>
<input type="button" value="btn1" />
<input type="button" value="btn2" />
<input type="button" value="btn3" />
来源：https://www.cnblogs.com/tongguilin/p/12193602.html