练习目标
1.点击按钮生成五位验证码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<button id="shen">点我生成验证码</button>
<div id="yan"> </div>
<script>
var oDiv = document.getElementById("yan");
var oButton = document.getElementById("shen");
yan(5, oDiv, oButton)
function yan(n, elem1, elem2) {
var str = "1234567890qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM";
function a(min, max) {
return number = Math.floor(Math.random() * (max - min + 1)) + min;
}
var c = "";
elem2.onclick = function () {
for (var i = 0; i < 2*n; i++) {
i++;
var number = a(0, str.length - 1);
c += str[number]
elem1.innerHTML = c;
if (((c.length) % n == 0)&&((c.length))!=n) {
elem1.innerHTML = c.slice((c.length-n), c.length);
}
}
}
}
</script>
</body>
</html>
2.显示倒计时

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
div {
margin-top: 40px;
width: 400px;
height: 35px;
border-top: 1px solid #f801bc;
border-bottom: 1px solid #e6e6e6;
text-align: right;
line-height: 35px;
color: #f5004b;
}
span {
display: inline-block;
width: 27px;
height: 27px;
background-color: #f5004b;
text-align: center;
line-height: 28px;
color: white;
border-radius: 5px;
}
span:nth-child(1) {
margin-right: 10px;
width: auto;
font-size: 14px;
color: #f5004b;
background-color: white;
}
</style>
</head>
<body>
<div>
<span>本场剩余时间</span>
<span>00</span> :
<span>00</span> :
<span>00</span>
</div>
</body>
<script>
ax()
setInterval(ax, 1000)
function ax() {
var oSpan = document.getElementsByTagName("span");
var oDate = new Date();
var future = new Date("2020,12,24")
var ms = future - oDate;
var hours = parseInt((ms / 60 / 60 / 1000) % 24);
var minite = parseInt((ms / 60 / 1000) % 60)
var s = parseInt((ms / 1000) % 60)
oSpan[1].innerHTML = hours;
oSpan[2].innerHTML = minite;
oSpan[3].innerHTML = s;
}
</script>
</html>
3.左边输入框输入需要替换的文字,右边输入替换文字,点击按钮替换文本框内文字
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
* {
margin: 0;
padding: 0;
outline-style: none;
}
div {
margin: 40px 100px;
width: 460px;
}
button {
margin-bottom: 20px;
}
p {
padding: 10px;
border: 8px solid #cccccc;
text-align: justify;
}
span {
background-color: #ffd700;
}
</style>
</head>
<body>
<div>
<input type="text" style="margin-left: 40px;"><input type="text"><button>确定</button>
<p>
微软必应(英文名:Microsoft Bing),原名必应(Bing),是微软公司于2009年5月28日推出,用以取代Live*
Search的全新搜索引擎服务。为符合中国用户使用习惯,Bing中文品牌名为“必应”。作为全球领先的搜索引擎之一, [1]
截至2013年5月,必应已成为北美地区第二大搜索引擎,如加上为雅虎提供的搜索技术支持,必应已占据29.3%的市场份额。
</p>
</div>
<script>
var oInput = document.getElementsByTagName("input");
var oButton = document.getElementsByTagName("button")[0];
var oP = document.getElementsByTagName("p")[0];
oButton.onclick = function () {
while(oP.innerHTML.indexOf(oInput[0].value)>0){
oP.innerHTML = oP.innerHTML.replace(oInput[0].value, "<strong>" + oInput[0].value.charCodeAt(0) + "</strong>");
}
while(oP.innerHTML.indexOf("<strong>" + oInput[0].value.charCodeAt(0) + "</strong>")>0){
oP.innerHTML = oP.innerHTML.replace("<strong>" + oInput[0].value.charCodeAt(0) + "</strong>", "<span>" + oInput[1].value + "</span>");
}
}
console.log(oInput[0].value.charCodeAt(0))
</script>
</body>
</html>
```