Paanch: Collections in C#

The null-coalescing operator ?? returns the value of its left-hand operand if it isn't null; otherwise, it evaluates the right-hand operand and returns its result. The ?? operator doesn't evaluate its right-hand operand if the left-hand operand evaluates to non-null.

The null-coalescing operator is right-associative, that is, an expression of the form

C#

a ?? b ?? c

is evaluated as

C#

a ?? (b ?? c)

The ?? operator can be useful in the following scenarios:

Paanch:

Peek -- points to an oldest element in the queue without removing it.

Example:

Queue<string> myQueue = new Queue<string>();

myQueue.Enqueue("1");
myQueue.Enqueue("2")

Then,

myQueue.Peek(); //will result "1"