前端学习之DOM编程案例：抽奖案例

代码

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>抽奖案例</title><style>*{margin: 0;padding: 0;}</style>
</head>
<body><div id="container"></div><script>let div0 = document.querySelector('#container')//最外边的大盒子div0.style.width = 800 +'px'div0.style.height = 900 +'px'div0.style.border = '1px dashed red'        div0.style.margin = 'auto'div0.style.textAlign = 'center'//抽奖显示的圆let cirle =  document.createElement('div')cirle.style.borderRadius = '50%'// cirle['borderRadius'] = '50%'// cirle['backgroundColor'] = 'red'cirle.style.backgroundColor = 'red'cirle.style.width = 300 + 'px'cirle.style.height = 300 + 'px'cirle.style.margin = 'auto'cirle.textContent = '宝马五元代金卷'cirle.style.fontSize = '30px'cirle.style.color = 'white'cirle.style.marginTop = '80px'cirle.style.lineHeight = '300px'cirle.style.textAlign='center'div0.appendChild(cirle)//抽奖按钮let button1 = document.createElement('button')button1.style.width=300+'px'button1.style.height=40+'px'button1.textContent = '开始抽奖'button1.style.margin='auto'button1.style.marginTop = 40+'px'let btn_status = '开始抽奖'//奖品let arr = ['宝马五元代金卷','兰博基尼五元代金卷','法拉利五元代金卷','iphone五元代金卷']    //抽奖逻辑button1.onclick = function(){if (btn_status == '开始抽奖'){id = setInterval(start,10)}else{btn_status = '开始抽奖'button1.textContent = btn_statusclearInterval(id)} }div0.appendChild(button1)function start(){index = Math.ceil(Math.random()*4)cirle.textContent = arr[index]btn_status = '停止抽奖'button1.textContent = btn_status}</script>
</body>
</html>