Objective-C:使用元素数组设置alpha值

// 导入UIKit框架
#import <UIKit/UIKit.h>

int main(int argc, char * argv[]) {
    @autoreleasepool {
        // 创建一个元素数组
        NSArray *elements = @[
            [[UIView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)],
            [[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)],
            [[UIView alloc] initWithFrame:CGRectMake(0, 0, 300, 300)]
        ];
        
        // 设置alpha值
        CGFloat alpha = 0.5;
        for (UIView *element in elements) {
            element.alpha = alpha;
        }
        
        // 打印设置后的alpha值
        for (UIView *element in elements) {
            NSLog(@"alpha: %f", element.alpha);
        }
    }
    return 0;
}