我有
enum Colour {
white,
pink,
yellow,
blue
} Colour;
我想这样做:
for (int colour in Colour){
// Do something here.
}
我可以这样做吗？如果可以，怎么做？谢谢你的帮助！
我有
enum Colour {
white,
pink,
yellow,
blue
} Colour;
我想这样做:
for (int colour in Colour){
// Do something here.
}
我可以这样做吗？如果可以，怎么做？谢谢你的帮助！
enum来自C，而fast enumeration是Objective-C2.0的补充..他们不在一起工作.
Type existingItem;
for ( existingItem in expression ) { statements }
表达式必须符合NSFastEnumeration协议，并且是一个对象！枚举的"元素"不是对象.
有关更多信息，请参见此链接
查看此示例以了解枚举的工作速度:
NSArray *array = [NSArray arrayWithObjects:
@"One", @"Two", @"Three", @"Four", nil];
for (NSString *element in array) {
NSLog(@"element: %@", element);
}
NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:
@"quattuor", @"four", @"quinque", @"five", @"sex", @"six", nil];
NSString *key;
for (key in dictionary) {
NSLog(@"English: %@, Latin: %@", key, [dictionary objectForKey:key]);
}