https://vrgl.ir/ngJVM

ref_vs_out_in_csharp.cs

void multiply(int number)
{
    number *= 2;
}

void add(ref int number)
{
    number += 1;
}

void subtract(out int number)
{
    number = 5;
    number -= 1;
}

int age = 10;

multiply(age);
Console.WriteLine(age);

add(ref age);
Console.WriteLine(age);

subtract(out age);
Console.WriteLine(age);