HTML Form Validation Required Pattern Min Max

Ringkasan

HTML punya validasi bawaan tanpa JS: required, type, pattern, min/max, minlength/maxlength. Browser menolak submit kalau tidak valid.

Konsep Dasar

• required — wajib diisi.
• type="email|url|number" — format otomatis divalidasi.
• pattern="[A-Za-z]+" — regex client-side.
• min/max/step (number/date), minlength/maxlength.
• :invalid / :valid CSS pseudo-class untuk feedback visual.

Cara Kerja / Struktur

html

<label for="user">User (huruf saja)</label>
<input id="user" name="user" pattern