Syntax ref out and in in C#

Syntax ref

ref Passes the argument by reference, allowing the method to read and modify the value. The variable must be initialized before being passed. ref It also changes the semantics if you use with a reference type like a or a . In the method below if you would not use the modifier, “myString” would still be “Original String” after the call due to the immutability of string

Syntax out

out Similar to , but the variable doesn’t need to be initialized before being passed. The method must assign a value before it returns. out You find this typical with the “Try” pattern where the return value is a boolean type and the value gets passed via out to the caller.

Syntax in

in Passes the argument by reference, but the method can only read the value, not modify it. Useful for performance when passing large structs.

Summary

• Use when you want to allow a method to read and modify a value

• Use when you want a method to initialize and return a value

• Use when you want to pass a large struct by reference without allowing modifications.