一些 NSArray 的基本操作代码例子

  数组可以说是软件开发人员每天都要面对的基本操作，下面就分享一些 NSArray 的基本操作代码例子供苹果开发初学者参考，每段代码第一行会以注释方式说明该段代码的用途。

/*******************************************************************************************
     NSArray
     *******************************************************************************************/

    /*---------------------------创建数组------------------------------*/
    //NSArray *array = ［NSArray alloc] initWithObjects:
    @"One",@"Two",@"Three",@"Four",nil];

    self.dataArray = array;
    [array release];

    //- (unsigned) Count;数组所包含对象个数；
    NSLog(@"self.dataArray cound:%d",[self.dataArray count]);

    //- (id) objectAtIndex: (unsigned int) index;获取指定索引处的对象;
    NSLog(@"self.dataArray cound 2:%@",[self.dataArray objectAtIndex:2]);


    /*--------------------------从一个数组拷贝数据到另一数组(可变数级)----------------------------*/    

    //arrayWithArray:
    //NSArray *array1 = ［NSArray alloc] init];
    NSMutableArray *MutableArray = ［NSMutableArray alloc] init];
    NSArray *array = [NSArray arrayWithObjects:
                      @"a",@"b",@"c",nil];
    NSLog(@"array:%@",array);
    MutableArray = [NSMutableArray arrayWithArray:array];
    NSLog(@"MutableArray:%@",MutableArray);

    array1 = [NSArray arrayWithArray:array];
    NSLog(@"array1:%@",array1);


    //Copy

    //id obj;
    NSMutableArray *newArray = ［NSMutableArray alloc] init];
    NSArray *oldArray = [NSArray arrayWithObjects:
                         @"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];

    NSLog(@"oldArray:%@",oldArray);
    for(int i = 0; i < [oldArray count]; i++)
    {        
        obj = ［oldArray objectAtIndex:i] copy];
        [newArray addObject: obj];
    }
    //     
    NSLog(@"newArray:%@", newArray);
    [newArray release];


    //快速枚举

    //NSMutableArray *newArray = ［NSMutableArray alloc] init];
    NSArray *oldArray = [NSArray arrayWithObjects:
                         @"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];    
    NSLog(@"oldArray:%@",oldArray);

    for(id obj in oldArray)
    {
        [newArray addObject: obj];
    }
    //     
    NSLog(@"newArray:%@", newArray);
    [newArray release];    


    //Deep copy

    //NSMutableArray *newArray = ［NSMutableArray alloc] init];
    NSArray *oldArray = [NSArray arrayWithObjects:
                         @"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];    
    NSLog(@"oldArray:%@",oldArray);    
    newArray = (NSMutableArray*)CFPropertyListCreateDeepCopy(kCFAllocatorDefault, (CFPropertyListRef)oldArray, kCFPropertyListMutableContainers);
    NSLog(@"newArray:%@", newArray);
    [newArray release];    


    //Copy and sort

    //NSMutableArray *newArray = ［NSMutableArray alloc] init];
    NSArray *oldArray = [NSArray arrayWithObjects:
                         @"b",@"a",@"e",@"d",@"c",@"f",@"h",@"g",nil];    
    NSLog(@"oldArray:%@",oldArray);
    NSEnumerator *enumerator;
    enumerator = [oldArray objectEnumerator];
    id obj;
    while(obj = [enumerator nextObject])
    {
        [newArray addObject: obj];
    }
    [newArray sortUsingSelector:@selector(compare:)];
    NSLog(@"newArray:%@", newArray);
    [newArray release];



    /*---------------------------切分数组------------------------------*/

    //从字符串分割到数组－ componentsSeparatedByString:
    NSString *string = ［NSString alloc] initWithString:@"One,Two,Three,Four"];
    NSLog(@"string:%@",string);    
    NSArray *array = [string componentsSeparatedByString:@","];
    NSLog(@"array:%@",array);
    [string release];


    //从数组合并元素到字符串- componentsJoinedByString:
    NSArray *array = ［NSArray alloc] initWithObjects:@"One",@"Two",@"Three",@"Four",nil];
    NSString *string = [array componentsJoinedByString:@","];
    NSLog(@"string:%@",string);



    /*******************************************************************************************
     NSMutableArray
     *******************************************************************************************/
    /*---------------给数组分配容量----------------*/
    //NSArray *array;
    array = [NSMutableArray arrayWithCapacity:20];



    /*--------------在数组末尾添加对象----------------*/
    //- (void) addObject: (id) anObject;
    //NSMutableArray *array = [NSMutableArray arrayWithObjects:
    @"One",@"Two",@"Three",nil];
    [array addObject:@"Four"];
    NSLog(@"array:%@",array);



    /*--------------删除数组中指定索引处对象----------------*/    
    //-(void) removeObjectAtIndex: (unsigned) index;    
    //NSMutableArray *array = [NSMutableArray arrayWithObjects:
    @"One",@"Two",@"Three",nil];
    [array removeObjectAtIndex:1];
    NSLog(@"array:%@",array);



    /*-------------数组枚举---------------*/    
    //- (NSEnumerator *)objectEnumerator;从前向后
    //NSMutableArray *array = [NSMutableArray arrayWithObjects:
    @"One",@"Two",@"Three",nil];
    NSEnumerator *enumerator;
    enumerator = [array objectEnumerator];

    id thingie;
    while (thingie = [enumerator nextObject]) {
        NSLog(@"thingie:%@",thingie);
    }


    //- (NSEnumerator *)reverseObjectEnumerator;从后向前
    //NSMutableArray *array = [NSMutableArray arrayWithObjects:
    @"One",@"Two",@"Three",nil];
    NSEnumerator *enumerator;
    enumerator = [array reverseObjectEnumerator];

    id object;
    while (object = [enumerator nextObject]) {
        NSLog(@"object:%@",object);
    }


    //快速枚举
    //NSMutableArray *array = [NSMutableArray arrayWithObjects:
    @"One",@"Two",@"Three",nil];
    for(NSString *string in array)
    {
        NSLog(@"string:%@",string);
    }



    /*******************************************************************************************
     NSDictionary
     *******************************************************************************************/

    /*------------------------------------创建字典------------------------------------*/
    //- (id) initWithObjectsAndKeys;

    //NSDictionary *dictionary = ［NSDictionary alloc] initWithObjectsAndKeys:@"One",@"1",@"Two",@"2",@"Three",@"3",nil];
    NSString *string = [dictionary objectForKey:@"One"];
    NSLog(@"string:%@",string);
    NSLog(@"dictionary:%@",dictionary);
    [dictionary release];


    /*******************************************************************************************
     NSMutableDictionary
     *******************************************************************************************/

    /*------------------------------------创建可变字典------------------------------------*/    
    //创建
    NSMutableDictionary *dictionary = [NSMutableDictionary dictionary];

    //添加字典
    [dictionary setObject:@"One" forKey:@"1"];
    [dictionary setObject:@"Two" forKey:@"2"];
    [dictionary setObject:@"Three" forKey:@"3"];
    [dictionary setObject:@"Four" forKey:@"4"];
    NSLog(@"dictionary:%@",dictionary);

    //删除指定的字典
    [dictionary removeObjectForKey:@"3"];
    NSLog(@"dictionary:%@",dictionary);


    /*******************************************************************************************
     NSValue（对任何对象进行包装）
     *******************************************************************************************/

    /*--------------------------------将NSRect放入NSArray中------------------------------------*/    
    //将NSRect放入NSArray中
    NSMutableArray *array = ［NSMutableArray alloc] init];
    NSValue *value;
    CGRect rect = CGRectMake(0, 0, 320, 480);    
    value = [NSValue valueWithBytes:&rect objCType:@encode(CGRect)];
    [array addObject:value];
    NSLog(@"array:%@",array);

    //从Array中提取
    value = [array objectAtIndex:0];
    [value getValue:&rect];
    NSLog(@"value:%@",value);


    /*******************************************************************************************
     从目录搜索扩展名为jpg的文件
     *******************************************************************************************/

    //NSFileManager *fileManager = [NSFileManager defaultManager];
    NSString *home;
    home = @"../Users/";

    NSDirectoryEnumerator *direnum;
    direnum = [fileManager enumeratorAtPath: home];

    NSMutableArray *files = ［NSMutableArray alloc] init];

    //枚举
    NSString *filename;
    while (filename = [direnum nextObject]) {
        if(［filename pathExtension] hasSuffix:@"jpg"]){
            [files addObject:filename];
        }
    }

    //快速枚举
    //for(NSString *filename in direnum)
    //{
    //    if(［filename pathExtension] isEqualToString:@"jpg"]){
    //        [files addObject:filename];
    //    }
    //}
    NSLog(@"files:%@",files);

    //枚举
    NSEnumerator *filenum;
    filenum = [files objectEnumerator];
    while (filename = [filenum nextObject]) {
        NSLog(@"filename:%@",filename);
    }

    //快速枚举
    //for(id object in files)
    //{
    //    NSLog(@"object:%@",object);
    //}