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Types that say what they are

A mutable class and a ladder of if/else. Make the type immutable and the decision one expression.

Beginner18 min on the clock5 graded checks · 100 pointsC# FoundationsPro

Graded by reading your code against the checklist below.

What you build

Turn the shipment into a record
Make its properties settable only at construction
Replace the if/else ladder with a switch expression
Match on the properties rather than reading them one at a time
Produce a changed copy without mutating the original

Done means

Same prices, a type nobody can mutate, and a decision in one expression.

How it is graded

Published in full, before you start — every point is one of these and there is nothing else.

Declare it as a record+25Records and pattern matching
Settable at construction, not afterwards+15Records and pattern matching
One switch expression, not a ladder+25Records and pattern matching
Copy with a change instead of mutating+20Records and pattern matching
Match on properties+15Records and pattern matching

What it teaches

Records and pattern matchingbeginner

A record is a type that cannot be changed after it is built, and a switch expression makes a decision the compiler can check for gaps — together they delete most of the if/else you would otherwise write.

The rest of C# Foundations

The wrong containerBeginner · 15 min Loops that want to be LINQBeginner · 18 min Where null gets inBeginner · 18 min Blocking the threadBeginner · 20 min Catching what you can handleBeginner · 16 min