NSString和NSMutableString常用方法+NSArray常用代码

原址：http://www.cocoachina.com/newbie/tutorial/2010/1013/2173.html

常见的NSString和NSMutableString方法：

NSString方法:

+(id) stringWithContentsOfFile:path encoding:enc error:err
创建一个新字符串并将其设置为path指定的文件的内容，使用字符编码enc，如果非零，则返回err中错误

+(id) stringWithContentsOfURL:url encoding:enc error:err
创建一个新的字符串，并将其设置为url的内容，使用字符编码enc，如果非零，则返回err中的错误

+(id) string
创建一个新的空字符串

+(id) stringWithString:nsstring
创建一个新的字符串，并将其设置为nsstring

-(id)initWithString:nsstring
将分配的字符串设置为nsstring

-(id) initWithContentsOfFile:path encoding:enc error:err
将字符串设置为path制定的文件的内容

-(id) initWithContentsOfURL:url encoding:enc error:err
将字符串设置为url(NSURL *)url的内容，使用字符编码enc，如果非零，则返回err中的错误

-(id) (UNSIgned int)length
返回字符串中的字符数目

-(unichar)characterAtIndex:i
返回索引i的Unicode字符

-(NSString *)substringFromIndex:i
返回从i开始知道结尾的子字符串

-(NSString *)substringWithRange:range
根据指定范围返回子字符串

-(NSString *)substringToIndex:i
返回从该字符串开始到索i的子字符串

-(NSComparator *)caseInsensitiveCompare:nsstring
比较两个字符串，忽略大小写

-(NSComparator *)compare:nsstring
比较两个字符串

-(BOOL)hasPrefix:nsstring
测试字符串是否以nsstring开始

-(BOOL)hasSuffix:nsstring
测试字符串是否以nsstrng结尾

-(BOOL)isEqualToString:nsstring
测试两个字符串是否相等

-(NSString *) capitalizedString
返回每个单词首字母大写的字符串（每个单词的其余字母转换为小写）

-(NSString *)lowercaseString
返回转换为小写的字符串

-(NSString *)uppercaseString
返回转换为大写的字符串

-(const char*)UTF8String
返回转换为UIF－8字符串的字符串

-(double)doubleValue
返回转换为double的字符串

-(float)floatValue
返回转换为浮点值的字符串

-(NSInteger)integerValue
返回转换为NSInteger整数的字符串

-(int)intValue
返回转换为整数的字符串

NSMutableString方法
+(id) stringWithCapacity:size
创建一个字符串，初始包含size的字符

-(id) initWithCapacity:size
使用初始容量为size的字符串来初始化字符串

-(void) setString:nsstring
将字符串设置为nsstring

-(void) appendString:nsstring
在接收者的末尾附加nsstring

-(void) deleteCharactersInRange:range
删除指定range中的字符

-(void) insertString:nsstring atIndex:i
以索引i为起始位置插入nsstring

-(void) replaceCharactersInRange:range withString:nsstring
使用nsstring替换range指定的字符

-(void) replaceOccurrencesOf
String:nsstring withString:nsstring2 options:opts range:range
根据选项opts。使用指定range中的nsstring2替换所有的nsstring。选项可以包括NSBackwardsSearch（从范围的结尾 开始搜索）NSAnchoredSearch(nsstring必须匹配范围的开始)，NSLiteralSearch(执行逐字节比较以及 NSCaceInsensitiveSearch的按位或组合)

NSArray的基本操作代码：

/*---------------------------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);
    //}