BitWithBite
HTML Worksheet
🌐 Form Validation
SCORE___ / 20
NameClassDate
After this worksheet you can
Use required, min/max, patternBuilt-in browser messagesmaxlength and minlengthClient vs server validation📚 Quick Recap
HTML5 ships a complete validation engine that runs before the form ever reaches your server. With the right attributes you can enforce required fields, minimum lengths, number ranges, and custom regex patterns — all without writing a single line of JavaScript. You also get CSS hooks to style valid and invalid states in real time.
🧠 Section A · Concept Check ● BEGINNER 4 × 1 = 4
1Make a field mandatory with:
2Regex checks use the attribute:
3Cap text length with:
4Client-side validation can be:
🧮 Section B · Problem Solving ● INTERMEDIATE 2 + 3×3 = 11
5<input required> blocks submits.
6min and max constrain inputs.
7Username field: required, 3-12 chars.
84-digit PIN with pattern.
9Why validate on BOTH client and server?
🚀 Section C · Challenge ● CHALLENGE 5
10What does :invalid let CSS do?
💭 Reflection — the most useful thing I learned:
A ___/4 B ___/11 C ___/5 Total ___/20
Teacher's Signature
Parent's Signature
✂ answer key — fold or cut before handing out
1-A 2-A 3-A 4-A | 5 empty 6 number/date 7 = <input required minlength="3" maxlength="12"> 8 = <input pattern="[0-9]{4}" title="4 digits"> 9 = Client = instant UX; server = security (client can be bypassed) | 10 = Style fields that fail validation (e.g. red border)