js正则表达式--标识符（6）
g 全局捕获，捕获完前边的，再次输入捕获后边的
i 忽略大小写
<!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>
</head>
<body>
<script>
var datestr = "time 2025-01-02 12.20.20 to 2099-01-02 12.20.20"
var regg = /\d{4}-\d{1,2}-\d{1,2}/g
var newdatastr1 = regg.exec(datestr)
console.log(newdatastr1[0].split("-").join("/"))
var newdatastr2 = regg.exec(datestr)
console.log(newdatastr2[0].split("-").join("/"))
//i 忽略大小写
var aa = /[a-z]/i
console.log(aa.test("aa"))
console.log(aa.exec("AA"))
</script>
</body>
</html>