Hexaware Technologies Senior .NET Developer Interview Questions and Answers

Single returns the only element of a sequence, or a default value if the sequence is empty. First returns the first element of a sequence, or a default value if the sequence contains no elements.

• Single throws an exception if the sequence contains more than one element, while First does not.

• Single is useful when you expect only one element in the sequence, while First is used when you just need the first element.

• Example...read more

ref is used for passing a variable by reference, out is used for returning a value from a method

• ref keyword is used to pass a variable by reference, allowing the method to modify the variable

• out keyword is used to return a value from a method, the variable passed must be assigned a value within the method

• ref parameters must be initialized before passing to the method, out parameters do not need to be initialized