What kind of operator is the == in the expression i == 20?

In the expression i == 20, the operator being used is specifically designed to compare two values for equality. This means the operation checks whether the value of 'i' is equal to 20. Recognizing that == is fundamentally used to evaluate if two expressions result in the same value clarifies its role in programming.

While 'equality operator' accurately describes this function, it's also important to note that this operator falls under the broader category of relational operators that deal with comparisons between values. However, the most precise terminology in this context is 'equality operator,' as it specifically denotes the action of determining equivalence.

The other options represent distinct conceptual types in programming. For instance, an arithmetic operator performs mathematical calculations, like addition or subtraction; a relational operator includes greater than or less than comparisons; and an assignment operator is used to assign values to variables. Therefore, the classification of '==' as an equality operator is the most fitting in this scenario, highlighting its purpose in evaluating whether two values are the same.