前端学习——Web API (Day6)
正则表达式
语法
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<script>
const str = 你好，振华
// 定义规则
const reg = /你好/
// 检查
console.log(reg.test(str))
</script>
</body>
</html>
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<script>
const str = 你好，振华
// 定义规则
const reg = /你好/
// 检查
console.log(reg.exec(str))
</script>
</body>
</html>
元字符
边界符
量词
字符类
案例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
span {
display: inline-block;
width: 250px;
height: 30px;
vertical-align: middle;
line-height: 30px;
padding-left: 15px;
}
.error {
color: red;
background: url(./images/error1.png) no-repeat left center;
}
.right {
color: green;
background: url(./images/right.png) no-repeat left center;
}
</style>
</head>
<body>
<input type="text">
<span></span>
<script>
const input = document.querySelector(input)
const span = input.nextElementSibling
const reg = /^[a-zA-Z0-9-_]{6,16}$/
input.addEventListener(blur,function(){
if(reg.test(this.value)){
span.innerHTML = 输入正确
span.className(right)
}
else{
span.innerHTML = 请输入6~16位的英文数字下划线
span.className(error)
}
})
</script>
</body>
</html>
修饰符
案例
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<textarea name="" id="" cols="30" rows="10"></textarea>
<button>发布</button>
<div>123</div>
<script>
const tx = document.querySelector(textarea)
const btn = document.querySelector(button)
const div = document.querySelector(div)
btn.addEventListener(click,function(){
div.innerHTML = tx.value.replace(/激情|基情/g,**)
tx.value=
})
</script>
</body>
</html>
综合案例
阶段案例
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通过多线程提高代码的执行效率例子