1. Only numbers are allowed
<input name="username" type="text"onkeyup="value=this.value.replace(//D+/g,'')">
2. Only English letters, numbers and underscores are allowed (the following two methods are implemented)
<input name="username" type="text"style="ime-mode:disabled"><input name="username" type="text"onkeyup="value=value.replace(/[^/w/.//]/ig,'')">
3. Only English letters, numbers and =@# are allowed to be entered
<input name="username" type="text" onkeyup="value=value.replace(/[^/w=@#]|_/ig,'')">
4. Only Chinese characters are allowed
<input name="username" type="text"onkeyup="value=value.replace(/[^/u4E00-/u9FA5]/g,'')">
1. Only numbers are allowed
<input name="username" type="text"onkeyup="value=this.value.replace(//D+/g,'')">
2. Only English letters, numbers and underscores are allowed (the following two methods are implemented)
<input name="username" type="text"style="ime-mode:disabled"><input name="username" type="text"onkeyup="value=value.replace(/[^/w/.//]/ig,'')">
3. Only English letters, numbers and =@# are allowed to be entered
<input name="username" type="text"onkeyup="value=value.replace(/[^/w=@#]|_/ig,'')">
4. Only Chinese characters are allowed
<input name="username" type="text" onkeyup="value=value.replace(/[^/u4E00-/u9FA5]/g,'')">
Only enter numbers: "^[0-9]*$".
Only n-bit numbers can be entered: "^/d{n}$".
Only numbers with at least n digits can be entered: "^/d{n,}$".
Only numbers in m~n are entered:. "^/d{m,n}$"
Only numbers starting with zero and non-zero are entered: "^(0|[1-9][0-9]*)$".
Only positive real numbers with two decimal places can be entered: "^[0-9]+(.[0-9]{2})?$".
Only positive real numbers with 1 to 3 decimal places can be entered: "^[0-9]+(.[0-9]{1,3})?$".
Only non-zero positive integers can be entered: "^/+?[1-9][0-9]*$".
Only non-zero negative integers can be entered: "^/-[1-9][]0-9"*$.
Only characters with length 3 can be entered: "^.{3}$".
Only strings composed of 26 English letters can be entered: "^[A-Za-z]+$".
Only strings composed of 26 capital English letters can be entered: "^[AZ]+$".
Only strings composed of 26 lowercase English letters can be entered: "^[az]+$".
Only strings composed of numbers and 26 English letters can be entered: "^[A-Za-z0-9]+$".
Only strings composed of numbers, 26 English letters, or underscores can be entered: "^/w+$".
Verify user password: "^[a-zA-Z]/w{5,17}$" The correct format is: start with a letter, length between 6 and 18, and can only contain characters, numbers and underscores.
Verify that it contains characters such as ^%&',;=?$/": "[^%&',;=?$/x22]+".
Only enter Chinese characters: "^[/u4e00-/u9fa5]{0,}$"
Only enter numbers and decimal points, and prevent pasting:
<input type=""text" onkeyup="value=value.replace(/[^0-9.]/g,''),dxfqlld();" onpaste="value=value.replace(/[^0-9.]/g,'')" oncontextmenu="value=value.replace(/[^0-9.]/g,'')" />