C# Notes

Style

Member names are PascalCase, which is wild.

decimal types

128-bit decimal types! These are really cool! Literals have an M suffix: 1.1M.

Checking for null

I’ve seen it suggested to use pattern matching: foo is not null. == can be overridden.

You can also use foo is { } which will generate a compile-time error if foo’s type is not nullable, which is nice, but goodness that syntax.

However! Maybe what you really want is the null-conditional operator: Nullable?.Foo().

Null coalescing

nullable ?? otherValue

Array sizes

Array lengths are fixed. Clear(array) sets all values to 0-ish and does not change the length. (There is a Resize<T>(array) method but it only works on one-dimensional arrays.)

When creating a new array, values are filled with null or zero-ish values.

Multi-dimensional arrays and arrays-of-arrays

int[,] a = new int[4, 5]

a.Length // 20
a.Rank // 2
a.GetLength(0) // 4

The type is the base type and dimensions, but not the length of those dimensions. int[] is distinct from int[,].

Arrays-of-arrays, but these can be jagged: foo[3][3]. foo.Length would be 3.

Array index from end

^n counts from the end; ^1 is the index of the last item. There is no element ^0, but you might use that with ranges.

Public get, private set

public Type Name { get; private set; }

readonly isn’t like Objective-C’s readonly; in C# it means the field is only assignable in the declaration or constructor.

Notes Linking Here

• Programming