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iOS NSString常用操作以及数据转化

来源:http://www.xtcsyb.com 作者:永利402游戏网站-永利402com官方网站 时间:2019-09-11 14:45

1、将NSData转化为NSString

IOS 常用字符串的操作

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

不可变字符串

2、将NSString 转化为NSData- dataUsingEncoding:(NSStringEncoding)encoding;3、载一个字符串中删除一个字符或字符串

将NSData转化为NSString
 NSString* str = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];
 [_display deleteCharactersInRange:NSMakeRange(index_of_char_to_remove, 1)];
将NSString 转化为NSData
  - (NSData *)dataUsingEncoding:(NSStringEncoding)encoding;  

4、从文件读取字符串:initWithContentsOfFile方法

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)];
 NSString *path = @"***.text"; NSString *astring = [[NSString alloc] initWithContentsOfFile:path];
数学转换为字符串
 NSString *returnStr;
 returnStr = [[NSNumber numberWithInt:row] stringValue];

5、写字符串到文件:writeToFile方法

创建字符串的方法

 NSString *astring = [[NSString alloc] initWithString:@"This is a String!"]; NSString *path = @"astring.text"; [astring writeToFile: path atomically: YES];
1、创建常量字符串。
 NSString *astring = @"This is a String!";  

6、比较两个字符串1>、用C比较:strcmp函数

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);  
char string1[] = "string!"; char string2[] = "string!"; if(strcmp(string1, string2) = = 0) { NSLog; }
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];  

2>、isEqualToString方法

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];  
NSString *astring01 = @"This is a String!"; NSString *astring02 = @"This is a String!"; BOOL result = [astring01 isEqualToString:astring02]; NSLog(@"result:%d",result);
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];  

3>、compare方法(comparer返回的三种值)

6、创建临时字符串
  NSString *astring; 
  astring = [NSString stringWithCString:"This is a temporary string"];  
  NSLog(@"astring:%@",astring);  
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 

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];  

7、改变字符串的大小写

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];      
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 

比较两个字符串

8、在字符串中搜索子串

1、用C比较:strcmp函数
 char string1[] = "string!";  
 char string2[] = "string!";  
 if(strcmp(string1, string2) = = 0)  
 {  
     NSLog(@"1");  
 }  
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]];
2、isEqualToString方法
 NSString *astring01 = @"This is a String!";  
 NSString *astring02 = @"This is a String!";  
 BOOL result = [astring01 isEqualToString:astring02];  
 NSLog(@"result:%d",result);  

9、截取子串1>、-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

3、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);      
NSString *string1 = @"This is a string"; NSString *string2 = [string1 substringToIndex:3]; NSLog(@"string2:%@",string2); 
4、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);  

2>、-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

5、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);       
NSString *string1 = @"This is a string"; NSString *string2 = [string1 substringFromIndex:3]; NSLog(@"string2:%@",string2); 
6、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);
    

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

7、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);       
    
NSString *string1 = @"This is a string"; NSString *string2 = [string1 substringWithRange:NSMakeRange]; NSLog(@"string2:%@",string2);

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。

10、获取扩展名:[Path pathExtension]

1、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  

11、判断是否以某个字符串开始或结尾

2、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];  
 - hasPrefix:(NSString *) aString; //开头 - hasSuffix:(NSString *) aString; //结尾
3、抽取子串

1、给字符串分配容量

-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);
NSMutableString *String; String = [NSMutableString stringWithCapacity:40]; 
-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);  

2、在已有字符串后面添加字符

-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);  
 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"]]; 
4、扩展路径
 NSString *Path = @"~/NSData.txt";  
 NSString *absolutePath = [Path stringByExpandingTildeInPath];  
 NSLog(@"absolutePath:%@",absolutePath);  
 NSLog(@"Path:%@",[absolutePath stringByAbbreviatingWithTildeInPath]);  

3、在已有字符串中按照所给出范围和长度删除字符

5、文件扩展名
 NSString *Path = @"~/NSData.txt";  
 NSLog(@"Extension:%@",[Path pathExtension]);  
 NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"]; [String1 deleteCharactersInRange:NSMakeRange]; 

可变字符串

4、在已有字符串后面在所指定的位置中插入给出的字符串

1、给字符串分配容量
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"]; [String1 insertString:@"Hi! " atIndex:0]; 
stringWithCapacity:
 NSMutableString *String;  
 String = [NSMutableString stringWithCapacity:40];  

5、将已有的空符串换成其它的字符串

2、在已有字符串后面添加字符
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"]; [String1 setString:@"Hello Word!"]; 
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);  

6、按照所给出的范围,和字符串替换的原有的字符

3、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);  
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"]; [String1 replaceCharactersInRange:NSMakeRange withString:@"That"]; 
4、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);  

7、判断字符串内是否还包含别的字符串

5、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);  

1>、检查字符串是否以另一个字符串开头- hasPrefix: (NSString *) aString;

6、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);  
NSString *String1 = @"NSStringInformation.txt"; [String1 hasPrefix:@"NSString"] = = 1 ? NSLog : NSLog; [String1 hasSuffix:@".txt"] = = 1 ? NSLog : NSLog; 
7、判断字符串内是否还包含别的字符串(前缀,后缀)

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

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");  

1、从字符串分割到数组

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;
NSString *string = [[NSString alloc] initWithString:@"One,Two,Three,Four"]; NSArray *array = [string componentsSeparatedByString:@","]; 

NSArray

2、从数组合并元素到字符串

创建数

 //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]);  
NSArray *array = [[NSArray alloc] initWithObjects:@"One",@"Two",@"Three",@"Four",nil]; NSString *string = [array componentsJoinedByString:@","]; 

从一个数组拷贝数据到另一数组(可变数级)

1>、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no2>、==:只判断指针数值,而不是它们所指向的内容3>、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来显示结果。

1、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);  
 typedef enum _NSComparisonResult{ NSOrderedAscending=-1; NSOrderedsame; NSOrderedDescending; } NSComparisonResult; 
2、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];  

4>、 compare: options: ( options 是一个位掩码,可以使用|添加选项标记选项 )options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

3、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];      
 NSError *parseError = nil; NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dict options:NSJSONWritingPrettyPrinted error:&parseError]; NSString *str = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding]; UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:str delegate:self cancelButtonTitle:@"不,谢了" otherButtonTitles:@"瞅瞅去", nil]; [alert show];
4、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];      

hasPrefixe 匹配字符串头haSuffix 匹配字符串的尾巴

5、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];  
NSString *string1 = @"卡拉是条狗"; NSString *string2 = @"狗狗叫卡拉"; //字符串以开头比较 if([string1 hasPrefix:@"卡拉"]) { NSLog(@"字符串string1以卡拉开头"); } //字符串以结尾比较 if([string2 hasSuffix:@"卡拉"]) { NSLog(@"string2字符串以卡拉结尾"); }

切分数组

1、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];  
2、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

1、创建
 NSMutableDictionary *dictionary = [NSMutableDictionary dictionary];  
2、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);  
3、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

1、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);  
2、从Array中提取
 value = [array objectAtIndex:0];
 [value getValue:&rect];
 NSLog(@"value:%@",value);  
3、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];  
4、枚举
 NSString *filename;
 while (filename = [direnum nextObject]) { 
     if([[filename pathExtension] hasSuffix:@"jpg"]){
          [files addObject:filename];
          }
 }  
5、快速枚举
 for(NSString *filename in direnum)
 {
     if([[filename pathExtension] isEqualToString:@"jpg"]){
             [files addObject:filename];
             }  
 }
  NSLog(@"files:%@",files);  
4.1枚举
 NSEnumerator *filenum; 
 filenum = [files objectEnumerator]; 
 while (filename = [filenum nextObject]) {
     NSLog(@"filename:%@",filename);
 }  
5.1快速枚举
 for(id object in files) 
 {
     NSLog(@"object:%@",object);
 }  
 #import <Foundation/Foundation.h>
      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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