Check If String Contains All “?”

Question

How can I check if a string contains all question marks? Like this:

string input = \"????????\";

Answer 1

bool allQuestionMarks = input.All(c => c == '?');

This uses the LINQ All method, which "determines whether all elements of a sequence satisfy a condition." In this case, the elements of the collection are characters, and the condition is that the character is equal to the question mark character.