2. Data Validation

Learn how validation checks are used to control the quality of data entered into a system.

Application Form — Spot the Errors

Presence CheckUniqueness CheckType CheckFixed Value CheckRange CheckLength CheckFormat CheckConsistency Check

Application Form

s034930
Uniqueness Check

The student with this ID has already applied.

 
Presence Check

Name must be entered.

15
Fixed Value Check

Sex must be either M or F.

M
Type Check

Age must be a number larger than 12.

2590872
Length Check

Phone number must be 8-digit.

alexchan.com
Format Check

Email address must contain an "@".

 
Presence Check

This field is required.

31/08/2025
01/08/2025
Consistency Check

The end date must come after the start date.

Data Validation — Which Check?

✓ 0 correct
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🧩A person's birth year is 2010 but their listed age is 30

Which category does this belong to?

Data Type Session

Enter a focused session to learn Integer, Float, String, and Boolean with quiz and practice games.

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