示例
NSArray *myColors = @[@"Red", @"Green", @"Blue", @"Yellow"];
//快速列举
//无法在循环内修改myColors
for (NSString *color in myColors) {
NSLog(@"Element %@", color);
}
//使用索引
for (NSUInteger i = 0; i < myColors.count; i++) {
NSLog(@"Element %d = %@", i, myColors[i]);
}
//使用块枚举
[myColors enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL * stop) {
NSLog(@"Element %d = %@", idx, obj);
//要中止使用:
*stop = YES
}];
//使用块枚举 with options
[myColors enumerateObjectsWithOptions:NSEnumerationReverse usingBlock:^(id obj, NSUInteger idx, BOOL * stop) {
NSLog(@"Element %d = %@", idx, obj);
}];