How can you create a method with default values for its parameters?
Sources & Resources
Main Source: đź”— Ace the iOS Interview
When we declare a function in Swift, we can specify defaults for our parameters by specifying values within the method declaration.
When we declare a function in Swift, we can specify defaults for our parameters by specifying values within the method declaration:
func sayHello(name: String = "reader")
Now, we can call this function directly without having to explicitly specify any parameters as the default values will be used instead.
If the function contains parameters that don’t have a default value specified, you’ll need to specify a value for that parameter as usual. Otherwise, the compiler will return a “missing argument” error.
Given this example function:
func sayHello(name: String = "reader") {
print("Hello, \(name)")
}
These two function calls are equivalent:
sayHello()
sayHello(name: "reader")
Now, let’s consider this function declaration:
func logStatement(prettyPrint: Bool = false, includeTimestamp: Bool, enableVerboseMode: Bool = false, message: String) {}
As you can see, there are several parameters with default values specified, but includeTimestamp and message are explicitly required. When we create functions with a mix of parameters like this, Xcode’s auto-complete will help enumerate all of the valid variations of the call to our function.
- Default Parameters: Swift allows you to specify default values for parameters within the function declaration.
- Flexibility in Function Calls: If parameters have default values, they can be omitted when calling the function.
- Required Parameters: Parameters without default values must be explicitly provided, otherwise, the compiler will throw an error.