The main use of out would be where your method needs to return more then one parameter.

See below example of TryParse Method

using System;

public class Example
{
public static void Main()
{
String[] values = { null, “160519”, “9432.0”, “16,667”,” -322 “, “+4302”, “(100);”, “01FA” };
foreach (var value in values)
{
int number;

bool success = Int32.TryParse(value, out number);
if (success)
{
Console.WriteLine(“Converted ‘{0}’ to {1}.”, value, number);
}
else
{
Console.WriteLine(“Attempted conversion of ‘{0}’ failed.”,
value ?? “<null>”);
}
}
}
}