Title here
Summary here
Variadic Functions in Objective-C
Variadic functions can be called with any number of trailing arguments. For example, fmt.Println is a common variadic function.
#import <Foundation/Foundation.h>
// Here’s a function that will take an arbitrary number of `int`s as arguments.
void sum(NSArray *nums) {
NSLog(@"%@ ", nums);
int total = 0;
// Within the function, the type of `nums` is equivalent to `NSArray`.
// We can call `count`, iterate over it with `for-in`, etc.
for (NSNumber *num in nums) {
total += [num intValue];
}
NSLog(@"%d", total);
}
int main(int argc, const char * argv[]) {
@autoreleasepool {
// Variadic functions can be called in the usual way with individual arguments.
sum(@[@1, @2]);
sum(@[@1, @2, @3]);
// If you already have multiple args in an array,
// apply them to a variadic function using like this.
NSArray *nums = @[@1, @2, @3, @4];
sum(nums);
}
return 0;
}To run the program, compile the code and execute the binary.
$ clang -fobjc-arc -framework Foundation variadic-functions.m -o variadic-functions
$ ./variadic-functions
[1 2] 3
[1 2 3] 6
[1 2 3 4] 10Another key aspect of functions in this language is their ability to form closures, which we’ll look at next.