HTML5 form validation có những attribute nào?

required (bắt buộc), pattern (regex), min/max (số/ngày), minlength/maxlength (chuỗi), step (bước nhảy).

• Input type email/url tự validate format.
• Dùng :valid/:invalid CSS pseudo-classes.

required (mandatory), pattern (regex), min/max (number/date), minlength/maxlength (string), step (increment).

• Input types like email and url automatically validate format.
• Use :valid/:invalid CSS pseudo-classes for visual feedback.