Hi lingers,
This is called conditional operator ?:, also known as the ternary conditional operator.
This evaluates a Boolean expression and returns the result of one of the two expressions depending on whether the Boolean expression evaluates to true or false, as the following example shows:
// condition ? statement 1 : statement 2
lblName.Text = !string.IsNullOrEmpty(name) ? name : " ";
If the name is not null or empty then lblName Text set as name else it will be set as .
For more details refer below link.
?: operator