Use the pattern attribute to set the regular expression that an <input> element’s value is checked. You can try to run the following code to implement pattern attribute −
Example
<!DOCTYPE html> <html> <head> <title>HTML novalidate attribute</title> </head> <body> <form action = "" method = "get" novalidate> Student Name<br><input type = "name" name = "sname"><br> Rank<br><input type = "number" name = "rank"><br> Student Country <br><input type = "text" name = "ccode" pattern="[A-Za-z]{3}" title = "country code"><br> <input type = "submit" value = "Submit"> </form> </body> </html>