為什么這樣無法實現呢？求解答 /(ㄒoㄒ)/~~ 代碼如下
<body>
?? ?<div class='title'>開始抽獎啦！</div>
?? ?<div class='btns' >
?? ??? ?<span class='start'>開 始</span>
?? ??? ?<span class='stop'>結 束</span>
?? ?</div>
?? ?<script>
?? ?var data=['紅米','白米','小米','大米','黑米','恭喜抽中騷豬','謝謝惠顧'];
?? ?window.onload=function(){
?? ??? ?
?? ??? ?var start=document.getElementsByClassName('start');
?? ??? ?var stop=document.getElementsByClassName('stop');
?? ??? ?var title=document.getElementsByClassName('title');
?? ??? ?start.onclick=function(){
?? ??? ??? ? timer=setInterval(function(){
?? ??? ??? ??? ?var random=Math.floor(Math.random()*data.length);
?? ??? ??? ??? ?console.log(random);
?? ??? ??? ??? ?// title.innerHTML=data[random];
?? ??? ??? ?},50);
?? ??? ?}
?? ?}
?? ?</script>
</body>
2019-09-02
<body><div?class='title'>開始抽獎啦！</div> <div?class='btns'?><button?class='start'>開?始</button> <button?class='stop'>結?束</button></div> <script> var?data=['紅米','白米','小米','大米','黑米','恭喜抽中騷豬','謝謝惠顧']; window.onload=function(){var?start=document.getElementsByClassName('start'); var?stop=document.getElementsByClassName('stop'); var?title=document.getElementsByClassName('title'); start[0].onclick=function(){function?timer(){var?random=Math.floor(Math.random()*data.length); console.log(random); title[0].innerHTML=data[random];}setInterval(timer,50);}} </script> </body> 你注意看getElementsByClassName中間有s，它是一個對象集合。上述是改過之后的代碼，你可以繼續寫完stop