meet it

copies a record and changes only what you name.

A record cannot change, but you often want one that is nearly the same. The word with copies a record and changes only the properties you name: monday with { Degrees = 17 }. Everything else is copied across as it was.

The original is left alone, so you can keep both. That makes with handy for a history, where each day's weather is its own record. Change several properties at once by separating them with commas inside the curly brackets.

using System;

var monday = new Weather("Leeds", 14, "cloudy");
var tuesday = monday with { Degrees = 17 };
var wednesday = tuesday with { Degrees = 12, Sky = "rainy" };
Console.WriteLine(monday);
Console.WriteLine(tuesday);
Console.WriteLine(wednesday);

record Weather(string Town, int Degrees, string Sky);

Monday still says 14 and cloudy at the end, because nothing ever changed it.

guess first

The basket gets bigger. What will this show?

Guess before you run it. Wrong guesses are how you learn, and nothing is marked.

using System;

var basket = new Basket("apples", 3);
var bigger = basket with { Count = 5 };
Console.WriteLine($"{basket.Count} {bigger.Count} {bigger.Fruit}");

record Basket(string Fruit, int Count);

your turn

Your turn. Level up a player.

Name your player on line 3. On line 4, copy them up to level 2. On line 5, copy that player with Health set to 60. Press run.

Your code

output

press run to see what happens

fix it

The sale price never shows. Fix it!

Broken code to fix

output

press run to see what happens

It shows 120, the old price. Which record does line 5 read the price from?
with left ticket alone. The new price lives in the copy called sale.
Change ticket.Price to sale.Price on line 5, then press run.

nailed it

you can copy and change in one go. :D

with copies a record and changes what you name.
The original record never changes.
Separate several changes with commas.

new words in your collection

with

This lesson isn’t saved. A free account remembers every lesson you finish.

with copies a record and changes only what you name.

The basket gets bigger. What will this show?

Your turn. Level up a player.

The sale price never shows. Fix it!

you can copy and change in one go. :D

copies a record and changes only what you name.