Out and Ref in C#

Question

Hi Friends I know out and ref are used to return more than one value from function but I want to know what is the differenece between them ? Please explain with an example ? Thanks

Maha · Answer

Here is the explanation from the book Ref parameter Variable values are given in the Main() method but can be altered by a method call. Out parameter Variable values are not given in the Main() method but can be obtained by a method call. The way I understood. But I am not an adept in C# therefore my explanation is questionable. //Reference Parameter using System; public class ParameterDemo2 { public static void Main() { int var = 4; Console.WriteLine("In Main var is {0}", var); MethodWithRefParam(ref var); //calling method with a reference parameter Console.WriteLine("In Main var is {0}", var); } public static void MethodWithRefParam(ref int parm) { parm = 888; Console.WriteLine("In MethodWithRefParam, param is {0}", parm); } } /* In Main var is 4 In MethodWithRefParam, param is 888 In Main var is 888 //Note that var value has been changed after method call */ //Out parameter using System; public class InputMethodDemo { public static void Main() { int first, second; InputMethod(out first, out second); //notice use of out Console.WriteLine("After InputMethod first is {0} and second is {1}", first, second); } //notice use of out public static void InputMethod(out int one, out int two) { string s1, s2; Console.Write("Enter first integer "); s1 = Console.ReadLine(); one = Convert.ToInt32(s1); Console.Write("Enter second integer "); s2 = Console.ReadLine(); two = Convert.ToInt32(s2); } } /* Enter first integer 2 Enter second integer 4 After InputMethod first is 2 and second is 4 */ /* Note that values for var are not given in the Main() method but obtained by a method call */

Out and Ref in C#

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