Introduction
In C#, the out keyword is used to indicate an output parameter in a method signature.
When combined with var, it allows you to declare an inline variable without explicitly specifying its type.
Adding an underscore _ after var is a convention to indicate that you're intentionally ignoring the output value of the method call.
Purpose
The out var _ syntax is commonly used when you're not interested in capturing the output value of a method call.
It's particularly useful for methods that return a boolean indicating success or failure, where you don't need the actual output value.
Example
public static bool IsValidIpAddress(string ipAddress)
{
return IPAddress.TryParse(ipAddress, out var _);
}
Consider the IPAddress.TryParse method in C#, which parses a string as an IP address.
You can use out var _ with this method to indicate that you're only interested in whether the parsing succeeds, not the parsed IPAddress object.
Usage
- By using out var _, you're essentially telling the compiler to discard the output value and focus only on the success or failure status of the method call.
- This can result in cleaner and more concise code, especially when you perform operations that don't require the output value.
Conclusion
Understanding out var _ in C# allows you to write more expressive and concise code by indicating your intent to ignore the output value of a method call.
It's a powerful feature for improving code readability and maintainability in various programming scenarios.