forum

Home / DeveloperSection / Forums / What's the difference between the “ref” and “out” keywords in C#?

Ask Question

What's the difference between the “ref” and “out” keywords in C#?

Steilla Mitchel11312-Jul-2023

What's the difference between the “ref” and “out” keywords in C#?

c#c# keyword research 
Updated on 13-Jul-2023
Steilla Mitchel

Steilla Mitchel

Follow
I completed my post-graduation in 2013 in the engineering field. Engineering is the application of science and math to solve problems. Engineers figure out how things work and find practical uses for scientific discoveries. Scientists and inventors often get the credit for innovations that advance the human condition, but it is engineers who are instrumental in making those innovations available to the world. I love pet animals such as dogs, cats, etc.

Can you answer this question?

Answer

1 Answers

Aryan Kumar

Aryan Kumar

13-Jul-2023

The ref and out keywords in C# are used to pass parameters by reference. However, there are some key differences between the two keywords.

  • ref parameters can be initialized before they are passed to the method. out parameters cannot be initialized before they are passed to the method.
  • ref parameters can be used to modify the value of the variable that is passed to the method. out parameters can only be used to get the value of the variable that is passed to the method.

In other words, ref parameters allow for bi-directional data flow, while out parameters only allow for unidirectional data flow.

Here is an example of how the ref keyword can be used:

C#

int myNumber = 10;

void DoSomething(ref int number)
{
    number = 20;
}

DoSomething(ref myNumber);

Console.WriteLine(myNumber); // This will print 20

In this example, the DoSomething() method takes a ref parameter called number. The ref keyword tells the compiler that the number parameter is a reference to the myNumber variable. This means that any changes that are made to the number parameter in the DoSomething() method will be reflected in the myNumber variable.

Here is an example of how the out keyword can be used:

C#

int myNumber = 10;

int AnotherNumber;

void DoSomething(out int number)
{
    number = 20;
}

DoSomething(out AnotherNumber);

Console.WriteLine(AnotherNumber); // This will print 20

In this example, the DoSomething() method takes an out parameter called number. The out keyword tells the compiler that the number parameter is a reference to a new variable that will be created in the DoSomething() method. This means that the number parameter cannot be initialized before it is passed to the DoSomething() method. However, the number parameter can be used to get the value of the new variable that is created in the DoSomething() method.

Liked By