What is pattern matching in Swift?
In Swift, there are two basic kinds of patterns: those that successfully match any kind of value, and those that may fail to match a specified value at runtime. The first kind of pattern is used for destructuring values in simple variable, constant, and optional bindings.
What does ~= mean in Swift?
The pattern-matching operator ( ~= ) is used internally in case statements for pattern matching. When you match against an Equatable value in a case statement, this operator is called behind the scenes.
What does case mean in Swift?
The case tests a pattern and if it matches then the following statement is executed. In your example the let next? is the pattern. If the value is unwrapped and assigned then the case matches and your code is executed. From the documentation: Optional Pattern.
What is pattern matching Haskell?
Overview. We use pattern matching in Haskell to simplify our codes by identifying specific types of expression. We can also use if-else as an alternative to pattern matching. Pattern matching can also be seen as a kind of dynamic polymorphism where, based on the parameter list, different methods can be executed.
Which operator performs a pattern matching?
Your answer LIKE operator is used for pattern matching, and it can be used as -. % – It matches zero or more characters.
What is nil in Swift?
In Swift, nil isn’t a pointer—it’s the absence of a value of a certain type. Optionals of any type can be set to nil , not just object types.
What is == in Swift?
First, == is the equality operator, which tests that two things are equal for whatever definition of “equal” those things use. For example, 5 == 5 is true because there == means an integer comparison, and the same is true for other built-in value types such as strings, booleans, and doubles.