ios 常用字符串的操作

//将NSData转化为NSString

NSString* str = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];

//将NSString 转化为NSData

(NSString.h)

- (NSData *)dataUsingEncoding:(NSStringEncoding)encoding;

//载一个字符串中删除一个字符或字符串

[_display deleteCharactersInRange:NSMakeRange(index_of_char_to_remove, 1)];

数学转换为字符串

NSString *returnStr;

returnStr = [[NSNumber numberWithInt:row] stringValue];

NSString

*******************************************************************************************/

//一、NSString

/*----------------创建字符串的方法----------------*/

//1、创建常量字符串。

NSString *astring = @"This is a String!";

//2、创建空字符串,给予赋值。

NSString *astring = [[NSString alloc] init];

astring = @"This is a String!";

[astring release];

NSLog(@"astring:%@",astring);

//3、在以上方法中,提升速度:initWithString方法

NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];

NSLog(@"astring:%@",astring);

[astring release];

//4、用标准c创建字符串:initWithCString方法

char *Cstring = "This is a String!";

NSString *astring = [[NSString alloc] initWithCString:Cstring];

NSLog(@"astring:%@",astring);

[astring release];

//5、创建格式化字符串:占位符(由一个%加一个字符组成)

int i = 1;

int j = 2;

NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@"%d.This is %i string!",i,j]];

NSLog(@"astring:%@",astring);

[astring release];

//6、创建临时字符串

NSString *astring;

astring = [NSString stringWithCString:"This is a temporary string"];

NSLog(@"astring:%@",astring);

/*----------------从文件读取字符串:initWithContentsOfFile方法----------------*/

NSString *path = @"astring.text";

NSString *astring = [[NSString alloc] initWithContentsOfFile:path];

NSLog(@"astring:%@",astring);

[astring release];

/*----------------写字符串到文件:writeToFile方法----------------*/

NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];

NSLog(@"astring:%@",astring);

NSString *path = @"astring.text";

[astring writeToFile: path atomically: YES];

[astring release];

/*----------------比较两个字符串----------------*/

//用C比较:strcmp函数

char string1[] = "string!";

char string2[] = "string!";

if(strcmp(string1, string2) = = 0)

{

NSLog(@"1");

}

//isEqualToString方法

NSString *astring01 = @"This is a String!";

NSString *astring02 = @"This is a String!";

BOOL result = [astring01 isEqualToString:astring02];

NSLog(@"result:%d",result);

//compare方法(comparer返回的三种值)

NSString *astring01 = @"This is a String!";

NSString *astring02 = @"This is a String!";

BOOL result = [astring01 compare:astring02] = = NSOrderedSame;

NSLog(@"result:%d",result);

//NSOrderedSame判断两者内容是否相同

NSString *astring01 = @"This is a String!";

NSString *astring02 = @"this is a String!";

BOOL result = [astring01 compare:astring02] = = NSOrderedAscending;

NSLog(@"result:%d",result);

//NSOrderedAscending判断两对象值的大小(按字母顺序进行比较,astring02大于astring01为真)

NSString *astring01 = @"this is a String!";

NSString *astring02 = @"This is a String!";

BOOL result = [astring01 compare:astring02] = = NSOrderedDescending;

NSLog(@"result:%d",result);

//NSOrderedDescending判断两对象值的大小(按字母顺序进行比较,astring02小于astring01为真)

//不考虑大小写比较字符串1

NSString *astring01 = @"this is a String!";

NSString *astring02 = @"This is a String!";

BOOL result = [astring01 caseInsensitiveCompare:astring02] = = NSOrderedSame;

NSLog(@"result:%d",result);

//NSOrderedDescending判断两对象值的大小(按字母顺序进行比较,astring02小于astring01为真)

//不考虑大小写比较字符串2

NSString *astring01 = @"this is a String!";

NSString *astring02 = @"This is a String!";

BOOL result = [astring01 compare:astring02

options:NSCaseInsensitiveSearch | NSNumericSearch] = = NSOrderedSame;

NSLog(@"result:%d",result);

//NSCaseInsensitiveSearch:不区分大小写比较 NSLiteralSearch:进行完全比较,区分大小写 NSNumericSearch:比较字符串的字符个数,而不是字符值。

/*----------------改变字符串的大小写----------------*/

NSString *string1 = @"A String";

NSString *string2 = @"String";

NSLog(@"string1:%@",[string1 uppercaseString]);//大写

NSLog(@"string2:%@",[string2 lowercaseString]);//小写

NSLog(@"string2:%@",[string2 capitalizedString]);//首字母大小

/*----------------在串中搜索子串----------------*/

NSString *string1 = @"This is a string";

NSString *string2 = @"string";

NSRange range = [string1 rangeOfString:string2];

int location = range.location;

int leight = range.length;

NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@"Location:%i,Leight:%i",location,leight]];

NSLog(@"astring:%@",astring);

[astring release];

/*----------------抽取子串 ----------------*/

//-substringToIndex: 从字符串的开头一直截取到指定的位置,但不包括该位置的字符

NSString *string1 = @"This is a string";

NSString *string2 = [string1 substringToIndex:3];

NSLog(@"string2:%@",string2);

//-substringFromIndex: 以指定位置开始(包括指定位置的字符),并包括之后的全部字符

NSString *string1 = @"This is a string";

NSString *string2 = [string1 substringFromIndex:3];

NSLog(@"string2:%@",string2);

//-substringWithRange: //按照所给出的位置,长度,任意地从字符串中截取子串

NSString *string1 = @"This is a string";

NSString *string2 = [string1 substringWithRange:NSMakeRange(0, 4)];

NSLog(@"string2:%@",string2);

//扩展路径

NSString *Path = @"~/NSData.txt";

NSString *absolutePath = [Path stringByExpandingTildeInPath];

NSLog(@"absolutePath:%@",absolutePath);

NSLog(@"Path:%@",[absolutePath stringByAbbreviatingWithTildeInPath]);

//文件扩展名

NSString *Path = @"~/NSData.txt";

NSLog(@"Extension:%@",[Path pathExtension]);

/*******************************************************************************************

NSMutableString

*******************************************************************************************/

/*---------------给字符串分配容量----------------*/

//stringWithCapacity:

NSMutableString *String;

String = [NSMutableString stringWithCapacity:40];

/*---------------在已有字符串后面添加字符----------------*/

//appendString: and appendFormat:

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];

//[String1 appendString:@", I will be adding some character"];

[String1 appendFormat:[NSString stringWithFormat:@", I will be adding some character"]];

NSLog(@"String1:%@",String1);

*/

/*--------在已有字符串中按照所给出范围和长度删除字符------*/

/*

//deleteCharactersInRange:

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];

[String1 deleteCharactersInRange:NSMakeRange(0, 5)];

NSLog(@"String1:%@",String1);

/*--------在已有字符串后面在所指定的位置中插入给出的字符串------*/

//-insertString: atIndex:

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];

[String1 insertString:@"Hi! " atIndex:0];

NSLog(@"String1:%@",String1);

/*--------将已有的空符串换成其它的字符串------*/

//-setString:

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];

[String1 setString:@"Hello Word!"];

NSLog(@"String1:%@",String1);

/*--------按照所给出的范围,和字符串替换的原有的字符------*/

//-setString:

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];

[String1 replaceCharactersInRange:NSMakeRange(0, 4) withString:@"That"];

NSLog(@"String1:%@",String1);

/*-------------判断字符串内是否还包含别的字符串(前缀,后缀)-------------*/

//01:检查字符串是否以另一个字符串开头- (BOOL) hasPrefix: (NSString *) aString;

NSString *String1 = @"NSStringInformation.txt";

[String1 hasPrefix:@"NSString"] = = 1 ?  NSLog(@"YES") : NSLog(@"NO");

[String1 hasSuffix:@".txt"] = = 1 ?  NSLog(@"YES") : NSLog(@"NO");

//02:查找字符串某处是否包含其它字符串 - (NSRange) rangeOfString: (NSString *) aString,这一点前面在串中搜索子串用到过;

/*******************************************************************************************

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);

//}

#import

int main (int argc, const char * argv[]) {

NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

//创建字符串

NSString *height;

/**类方法:

+(id) stringWithFormat: (NSString *) format,...

通过格式字符串和参数来创建NSString

省略号(。。。):可以接受多个以逗号分割的参数。

这声明方法时添加加号(+),那么这个方法为类方法,不需要创建实例就可以调用,通常用于创建心的实例,我们称用来创建新对象的类方法为工厂方法。

-------------------

objective-c运行时生成一个类的时候,它会创建一个代表该类的类对象。类对象包含了指向超类的指针,类名,和指向类方法列表的指针。类对象还包含一个long型数据,为新创建的类实例对象指定大小(以字节为单位)

类方法可以用来访问全局数据。

实例方法要用前导减号(-)来开始声明

*/

height=[NSString stringWithFormat:@"you heigh is %d feet,%d inches",5,11];

NSLog(height);

//length 返回字符串中字符的个数。-(unsigned int) length;

if([height length]>5){

NSLog(@"height length ------");

}

//字符串比较

/**

isEqualToString :可以用来比较接收方和当作参数传递来的字符串的内容是否相同,返回yes和no

*/

NSString *thing1=@"hello";

NSString *thing2=[[NSString alloc] initWithString:@"hello"];

if([thing1 isEqualToString:thing2]){

NSLog(@"they are same");

}

/**

==:只判断指针数值,而不是它们所指向的内容

*/

if(thing1==thing2){

NSLog(@"== same");

}

/*

compare:比较两个字符串。区分大小写

compare将接收对象和传递来的字符串逐个字符的进行比较,它返回一个NSComparisonResult(枚举类型)来显示结果。

typedef enum _NSComparisonResult{

NSOrderedAscending=-1;

NSOrderedsame;

NSOrderedDescending;

} NSComparisonResult;

*/

[thing1 compare:thing2];

if(NSOrderedSame==[thing1 compare:thing2]){

NSLog(@"compare same");

}

//compare:options:

/***

-(NSComparisonResult) compare:(NSString *) string

options:(unsinged) mask;

options 是一个位掩码,可以使用|添加选项标记

选项:

NSCaseInsensitiveSearch:不区分大小写字符

NSLiteralSearch:进行完全比较,区分大小写

NSNumbericSearch:比较字符串的字符个数,而不是字符值

*/

if([thing1 compare:thing2 options:NSCaseInsensitiveSearch|

NSNumericSearch]==NSOrderedSame){

NSLog(@"they match");

}

/**

以某个字符串开始或结尾

-(BOOL) hasPrefix:(NSString *) aString;

-(BOOL) hasSuffix:(NSString *) aString;

*/

NSString *fileName=@"aabbbcc";

if([fileName hasPrefix:@"aa"]){

NSLog(@"begin with aa");

}

if([fileName hasSuffix:@"cc"]){

NSLog(@"end with cc");

}

//NSMutableString 可变字符串

//SString 是不可变的,一旦NSString 被创建了,我们就不能改变它。

//+(id) stringWithCapacity:(unsinged) capacity; capacity:是给NSMutableString的一个建议,字符串的大小并不局限于所提供的大小,这个容量仅是个最优值。

NSMutableString *str=[NSMutableString stringWithCapacity:40];

[str appendFormat:@"sdfsdf%d",5];

[str appendString:@"ssssssss"];

NSLog(str);

//删除字符串

//-(void) deleteCharactersInRange:(NSRange) range;

NSMutableString *ms;

ms=[NSMutableString stringWithCapacity:50];

[ms appendString:@"aabbccdd"];

NSRange range;

range=[ms rangeOfString:@"cc"];

[ms deleteCharactersInRange:range];

NSLog(ms);

//与实例方法一样,继承对类方法也同样适用

//------------------集合--------------

//NSArray ,NSDictionary

/**

NSArray 是一个cocoa类,用来存储对象的有序列表。

NSArray有两个限制:1,它只能存储objective-c的对象,而不能存储c语言中的基本数据类型如int,float,enum,struct,或者nsarray中的随机指针。2,不能这nsarray中存储nil

类方法:

arrayWithObjects:创建一个新的nsarray。发送一个以逗号分割的对象列表,这列表结尾添加nil代表列表结束,(这就是不能这nsarray中存储nil的原因)

*/

NSArray *array=[NSArray arrayWithObjects:@"aa",@"bb",@"cc",nil];

//-(unsigned) count; 取得包含对象的个数

//-(id) objectAtIndex:(unsigned int) index; 取得索引位置的对象

int i;

for (i=0; i<[array count]; i++) {

NSLog(@"index %d has %@",i,[array objectAtIndex:i]);

}

//------------切分数组

//-componentsSeparatedByString:

NSString *ns=@"sdf,dsfs,dfd,fdf,df,dd";

NSArray *comArr=[ns componentsSeparatedByString:@","];

for(int i=0;i<[comArr count];i++){

NSLog(@"componentsSeparatedByString===%@",[comArr objectAtIndex:i]);

}

//componentJoinedByString: 合并nsarray中的元素来创建字符串

NSString *joinedStr=[comArr componentsJoinedByString:@"-->"];

NSLog(@"joined---= %@",joinedStr);

//可变数组

NSMutableArray *mutableArr=[NSMutableArray arrayWithCapacity:40];

[mutableArr addObject:@"aa"];

[mutableArr addObject:@"bb"];

[mutableArr addObject:@"cc"];

[mutableArr addObject:@"dd"];

for(int i=0;i<[mutableArr count];i++){

NSLog(@"mutableArr==%@",[mutableArr objectAtIndex:i]);

}

//-----  -(void) removeObjectAtIndex:(unsinged) index; 删除指定索引的对象,

//删除一个对象之后,数组中并没有留下漏洞,被删除对象后面的数组元素的哦被前移来填补空缺

[mutableArr removeObjectAtIndex:2];

for(int i=0;i<[mutableArr count];i++){

NSLog(@"removeObjectAtIndex == %@",[mutableArr objectAtIndex:i]);

}

//枚举

//NSEnumerator ,它是cocoa用来描述这种集合迭代运输的方法

//-(NSEnumerator *) objectEnumerator;

NSEnumerator *enumerator=[mutableArr objectEnumerator];

id thingie;

while(thingie=[enumerator nextObject]){

NSLog(@"i found %@",thingie);

}

//快速枚举

for(NSString *string in mutableArr){

NSLog(@"for in == %@",string);

}

//NSDictionary 字典

/*

NSDictionary 是在给定的关键字(通常是一个NSString字符串)下存储一个数值(可以是任何类型的对象)。然后你可以用这个关键字来查找相应的数值。

NSDictionary 是键查询的优化存储方式。它可以立即找出要查询的数据,而不需要遍历整个数组进行查找。

+(id) dictionaryWithObjectAndKeys:(id) firstObject,....;

该方法接收对象和关键字交替出现的系列,以nil值作为终止符号。

**/

NSDictionary *dic=[NSDictionary dictionaryWithObjectsAndKeys:@"aaa",@"a",@"bbb",@"b",nil];

NSString *dicStr=[dic objectForKey:@"a"];

if([dicStr isEqualToString:@"aaa"]){

NSLog(@"------------00000000000000000");

}

//可变字典

NSMutableDictionary *mutableDic=[NSMutableDictionary dictionaryWithCapacity:50];

[mutableDic setObject:@"1111" forKey:@"1"];

[mutableDic setObject:@"222" forKey:@"2"];

//删除 -(void) removeObjectForKe:(id) key;

[mutableDic removeObjectForKey:@"2"];

NSArray *keyArr=[mutableDic allKeys];

for(NSString *str in keyArr){

NSLog(@"key== %@",str);

NSLog(@"value== %@",[mutableDic objectForKey:str]);

}

//各种数值,NSNumber NSValue

/*

cocoa 提供了NSNumber类来包装基本数据类型

+(NSNumber *) numberWithChar:(char) value;

+(NSNumber *) numberWithInt:(int) value;

+(NSNumber *) numberWithFloat:(float) value;

+(NSNumber *) numberWthiBool:(BOOL) value;

-(char) charValue;

-(int) intVlaue;

-(float) floatValue;

-(BOOL) boolValue;

-(NSString *) stringValue;

**/

NSNumber *number;

number=[NSNumber numberWithInt:3];

[mutableDic setObject:number forKey:@"int"];

int num=[[mutableDic objectForKey:@"int"] intValue];

NSLog(@"int object value== %d",num);

//NSValue .NSNumber实际上是NSValue的子类,NSValue可以包装任意值

/**

+(NSValue *) valueWithBytes:(const void *) value objCType:(const char *) type;

传递的参数是你想要包装的数值的地址,通常,得到的是你想要存储的变量的地址(在c语言里适用操作符 & ),你也可以提供一个描述这个数据类型的字符串,通常用来说明struct中实体的类型和大小。你不用自己写代码

来生成这个字符串,@encode编译器指令可以接受数据类型的名称并为你生成合适的字符串

*/

NSRect rect= NSMakeRect(1, 2, 30, 40);

NSValue *value;

value=[NSValue valueWithBytes:&rect objCType:@encode(NSRect)];

NSMutableArray *mr=[NSMutableArray arrayWithCapacity:50];

[mr addObject:value];

//getValue 提取数据

/**

-(void) getValue:(void *) value; 要传递的是存储这个数值的变量的地址

*/

/***

value=[mr objectAtIndex:0];

NSRect r;

NSLog(@"00000 ===%@",r);

[value getValue:&r];

NSLog(@"111== %@",r);

*/

/**

+(NSValue *) valueWithPoint:(NSPoint) point;

+(NSValue *) valueWithSize:(NSSize) size;

+(NSValue *) valueWithRect:(NSRect) rect;

-(NSPoint) pointValue;

-(NSSize) sizeValue;

-(NSRect) rectValue;

*/

//NSNull

/*

*+(NSNull *) null;

*/

[mutableDic setObject:[NSNull null] forKey:@"fax"];

id fax;

fax=[mutableDic objectForKey:@"fax"];

if(fax==[NSNull null]){

NSLog(@"pppppppppppppppppp");

}

[pool drain];

return 0;

}

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