How can we determine if a string variable fullAddress contains a particular streetName?

Choosing the right method to determine if a string contains another string is crucial in programming. In this case, utilizing the method that checks for substring presence is essential.

The correct method, which is the one that involves fullAddress.Contains(streetName), specifically checks if the fullAddress string contains the streetName string. The Contains method is a built-in function in many programming languages that returns true if the specified substring exists within the string it is called on. This is a straightforward and effective approach to achieving the desired check.

In contrast, the other options present methods that do not function as intended. The Exists method is incorrect here as it is typically not associated with string operations—it's often related to collections or other data structures to check for the existence of elements, not substrings.

The method HasValue is also misapplied in this context, as it generally pertains to nullable types in some languages rather than checking for the presence of a substring within a string. Lastly, streetName.Contains(fullAddress) is inverted logic; it checks if the streetName contains fullAddress, which does not address the requirement of finding if streetName is part of fullAddress.