Understanding the 'ref' Keyword in C#

The "ref" keyword is used to indicate that a parameter is passed by reference to a method. When you pass a variable using the "ref" keyword, any changes made to the parameter inside the method will also affect the original variable outside the method.

Usage of "ref" keyword in C#:

public void ModifyValue(ref int number)
{
    number = 10; // Modifying the value of 'number' will affect the original variable passed as an argument.
}

To call the method with the "ref" parameter, you need to explicitly use the "ref" keyword both when defining the method and when passing the argument:

int value = 5;
ModifyValue(ref value); // 'value' will now be 10, as it was modified inside the method.

It's important to note that when using the "ref" keyword, the variable passed as an argument must be initialized before it's passed to the method. This ensures that the method has a valid reference to work with.

The "ref" keyword is particularly useful when you want to modify the value of a variable within a method and have those changes reflected back in the original variable outside the method. It is often used when you need to return multiple values from a method or when you want to avoid creating unnecessary object copies.