Objective-c自學筆記(3)-資料集合的使用

按書上的例子敲了敲：

#import <Foundation/Foundation.h>int main(int argc,const char *argv[]){    @autoreleasepool {        //聲明檔案管理對象        NSFileManager *manager;        //由defaultManager方法建立NSFileManager初始化        manager = [NSFileManager defaultManager];        //聲明要遍曆路徑        NSString *home;        //初始化要遍曆的目錄:使用者根目錄        home = [@"~" stringByExpandingTildeInPath];        //聲明檔案遍曆對象        NSDirectoryEnumerator *direnum;        //初始設定檔案遍曆對象,用檔案目錄對象home作參        direnum = [manager enumeratorAtPath:home];        //可變列表來儲存遍曆的檔案        NSMutableArray *files;        //初始化大小設定為42        files = [NSMutableArray arrayWithCapacity:42];        //枚舉迭代的對象        NSString *filename;        //使用迭代對象的方法來逐個遍曆枚舉中的所有元素        while(filename =[direnum nextObject]){            //判斷檔案是否是jpg格式的檔案            if([[filename pathExtension] isEqualTo:@"jpg"]){                //將檔案名稱添加到列表中                [files addObject:filename];            }        }        //聲明檔案清單枚舉        NSEnumerator *fileenum;        //初始化枚舉對象        fileenum = [files objectEnumerator];        //枚舉遍曆所有元素        while (filename=[fileenum nextObject]) {            //列印資訊            NSLog(@"%@",filename);        }    };//autoreleasepool    return 0;}//main

輸出

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