Input validation
Validation constrains data shape, ranges, and allowed values.
What it is
Validation constrains data shape, ranges, and allowed values.
When to use it
Validate every untrusted boundary and enforce business invariants separately.
Syntax
// Bad: trust input directly
$amount = $request->input("amount_cents");
// Good:
$data = $request->validate(["amount_cents" => "required|integer|min:1|max:100000000"]);Example
$data = $request->validate([
"amount_cents" => "required|integer|min:1|max:100000000",
"currency" => "required|in:USD,EUR",
]);
// Then authorize the account and check permitted balance/state.Common mistakes
Do not confuse sanitization with validation; allowed syntax may still violate a business rule.