onclick 点击不生效，但是每次刷新就能触发一次
<html>
<head>
<title>var that = this</title>
</head>
<body>
<p id="demo">1234</p>
<button id="btn">随机点名</button>
</body>
<script>
let demo = document.getElementById("demo");
let btn = document.getElementById("btn");
let names = ['小明', '张强', '迪子鄂', '车兮', '乌镇可', '髭须', '貔貅', '饕餮', '魍魉', '魑魅'];
let ranarr = function(arr) {
let rannum = Math.ceil(Math.random() * 10);
return arr[rannum - 1];
}
let dm = function(tdemo, arr, callback) {
demo.innerHTML = ranarr(names);
}
let dj = function() {
console.log('按钮被点击')
}
btn.onclick = dm(demo, names, ranarr);
</script>
</html>
