NSString常用方法

最近写代码用到比较多的字符串操作的,所以找到一个objective-c中字符串操作的汇总,和大家分享!

 

//创建字符串对象数组

 NSArray *array = [str componentsSeparatedByString:@"@"];//就是以@为标示 输出看看啦

 

 int count=[array count];

 int i;

 for(i=0;i<count;i=i+4)

 {

  printf("%i:  %s\n",i,[[array objectAtIndex:i] UTF8String]);

 }

  可变的字符串类

 NSMutableString *song=[[NSMutableString alloc] init];

 [song appendString:@"Deaf Leppard"];

 printf("%s\n",[song UTF8String]);

 

 NSRange range=[song rangeOfString:@"Deaf"];//获取字符串"Deaf"字串的范围

 [song replaceCharactersInRange:range withString:@"Def"];//替换

 printf("%s\n",[song UTF8String]);

 

 [song insertString:@"Animal by " atIndex:0];

 printf("%s\n",[song UTF8String]);

 

 [song release];

 

字典加数组操作

 NSArray *keys=[@"one two three" componentsSeparatedByString:@""];

 NSArray *value=[@"two bravo a" componentsSeparatedByString:@""];

 NSDictionary *dic=[[NSDictionary alloc] initWithObjects:value forKeys:keys];

 printf("%s\n",[[dic description] UTF8String]);

 

 

    //一、NSString   

  

 

    //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);

 

 

 

 

       

 

    NSString *path = @"astring.text";

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

    NSLog(@"astring:%@",astring);

    [astring release];

 

 

       

 

 

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

    NSLog(@"astring:%@",astring);

    NSString *path = @"astring.text";   

    [astring writeToFile: path atomically: YES];

    [astring release];   

 

 

 

 

           

 

    //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。

 

 

       

 

    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

 

 

           

 

    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];

 

 

           

 

    //-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]);

 

 

 

 

       

 

  

    //stringWithCapacity:

    NSMutableString *String;

    String = [NSMutableString stringWithCapacity:40];

 

 

       

 

    //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);

    */

 

 

       

  

 

    //-insertString: atIndex:

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

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

    NSLog(@"String1:%@",String1);

 

 

 

  

 

    //-setString:

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

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

    NSLog(@"String1:%@",String1);

 

 

 

  

 

    //-setString:

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

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

    NSLog(@"String1:%@",String1);

 

 

 

  

    //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 *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]);

 

 

       

 

    //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];

 

 

 

  

 

    //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);

 

 

 

  

  

    NSArray *array;

    array = [NSMutableArray arrayWithCapacity:20];

 

 

 

  

    //- (void) addObject: (id) anObject;

    NSMutableArray *array = [NSMutableArray arrayWithObjects:

    @"One",@"Two",@"Three",nil];

    [array addObject:@"Four"];

    NSLog(@"array:%@",array);

 

 

 

       

    //-(void) removeObjectAtIndex: (unsigned) index;   

    NSMutableArray *array = [NSMutableArray arrayWithObjects:

    @"One",@"Two",@"Three",nil];

    [array removeObjectAtIndex:1];

    NSLog(@"array:%@",array);

 

 

 

       

    //- (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);

    }

 

 

 

  

 

  

    //- (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];

 

 

  

 

       

    //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);

 

 

  

 

       

    //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);

 

 

  

 

    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);

    //}

原文地址:https://www.cnblogs.com/lm3515/p/2546103.html