您的位置:首页 > 移动开发 > IOS开发

ios 常用字符串的操作

2014-04-15 14:10 405 查看
//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];

 

 

 

int转为NSString

    for (int Abb_Appid=500001; Abb_Appid<500012; Abb_Appid++) {

        NSString *Abb_AppID_ID=[NSString stringWithFormat:@"%d",Abb_Appid];

    }

 

 NSString *tempA = @"123";

  NSString *tempB = @"456";

1,字符串拼接

 NSString *newString = [NSString stringWithFormat:@"%@%@",tempA,tempB];

2,字符转int

int intString = [newString intValue];

3,int转字符

NSString *stringInt = [NSString stringWithFormat:@"%d",intString];

4,字符转float

 float floatString = [newString floatValue];

5,float转字符

NSString *stringFloat = [NSString stringWithFormat:@"%f",intString];

 

     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 <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;  

    } 
内容来自用户分享和网络整理,不保证内容的准确性,如有侵权内容,可联系管理员处理 点击这里给我发消息
标签:  ios