NSNumber + (NSNumber *)numberWithInt:(int)value; + (NSNumber *)numberWithDouble:(double)value; - (int)intValue; - (double)doubleValue; //NSNumber可以将基本数据类型包装起来,形成一个对象,这样就可以给其发送消息,装入NSArray中等等。 NSNumber * intNumber=[NSNumber numberWithInt:100]; NSNumber *floatNumber=[NSNUmber numberWithFloat:100.00]; int i=[intNumber intValue]; if([intNumber isEqualToNumber:floatNumber]) .... //NSNumber继承NSObject ,可以使用比较 compare: isEqual等消息 NSString //一个NSString对象可以存储一段Unicode字符。在cocoa中,所有和字符、字符串相关的处理都是使用NSString来完成。 NSObject -> NSString // NSString继承自NSObject +(id) stringWithContentsOfFile:path encoding:enc error:err; +(id) stringWithContentsOfURL:url encoding:enc error:err; +(id) stringWithString:nsstring; //创建一个新的字符串,并将其设置为nsstring -(id)initWithFormat:(NSString *)format, ... ; -(id)initWithString:nsstring; //将分配的字符串设置为nsstring - (BOOL)isEqualToString:(NSString *)string; - (BOOL)hasPrefix:(NSString *)string; - (int)intValue; - (double)doubleValue; - (NSString *)stringByAppendingString:(NSString *)string; // 给一个字符串附加一个字符串string。 - (NSString *)stringByAppendingFormat:(NSString *)string; - (NSString *)stringByDeletingPathComponent; //-----创建字符串的方法----- //1、创建常量字符串 NSString *astring = @"This is a String!"; //2、先创建一个空的字符串,然后赋值; // alloc和init组合则适合在函数之间传递参数,用完之后需要手工release NSString *astring = [[NSString alloc] init]; astring = @"This is a String!"; NSLog(@"astring:%@",astring); [astring release]; //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、创建临时字符串 NSString *astring; astring = [NSString stringWithCString:"This is a temporary string"]; NSLog(@"astring:%@",astring); // OR NSString * scriptString = [NSString stringWithString:@" tell application \"Mail\"\r"]; //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]; //-----从文件读取字符串----- NSString *path = @"astring.text"; NSString *astring = [[NSString alloc] initWithContentsOfFile:path]; NSLog(@"astring:%@",astring); [astring release]; //-----写字符串到文件---- 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----- //1、用C比较:strcmp函数 char string1[] = "string!"; char string2[] = "string!"; if(strcmp(string1, string2) = = 0) { NSLog(@"1"); } //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); //3、compare方法(comparer返回的三种值:NSOrderedSame,NSOrderedAscending,NSOrderedDescending) NSString *astring01 = @"This is a String!"; NSString *astring02 = @"This is a String!"; BOOL result = [astring01 compare:astring02] = = NSOrderedSame; //NSOrderedSame// 判断两者内容是否相同 NSLog(@"result:%d",result); 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) //4、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) //5、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]);//uppercaseString返回转换为大写的字符串 NSLog(@"string2:%@",[string2 lowercaseString]);//lowercaseString返回转换为小写的字符串 NSLog(@"string2:%@",[string2 capitalizedString]);//capitalizedString返回每个单词首字母大写的字符串 //-----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 ----- //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 NSString *string1 = @"This is a string"; NSString *string2 = [string1 substringToIndex:3]; NSLog(@"string2:%@",string2); //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 NSString *string1 = @"This is a string"; NSString *string2 = [string1 substringFromIndex:3]; NSLog(@"string2:%@",string2); //3、-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); //4、快速枚举 for(NSString *filename in direnum) { if([[filename pathExtension] isEqualToString:@"jpg"]){ [files addObject:filename]; } } NSLog(@"files:%@",files); //5、枚举 NSEnumerator *filenum; filenum = [files objectEnumerator]; while (filename = [filenum nextObject]) { NSLog(@"filename:%@",filename); } @"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----- //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); //-----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]; } } //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]); //-----查找与替换----- - (NSString *)stringByReplacingCharactersInRange:(NSRange)range withString:(NSString *)replacement - (NSString *)stringByReplacingOccurrencesOfString:(NSString *)target withString:(NSString *)replacement //NSMutableString(可修改的字符串) NSObject -> NSString -> NSMutableString Common NSMutableString methods + (id)string; - (void)appendString:(NSString *)string; - (void)appendFormat:(NSString *)format, ...; //-----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删除字符---- //deleteCharactersInRange: NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"]; [String1 deleteCharactersInRange:NSMakeRange(0, 5)]; // 删除指定范围(location=0,length=5)的字符串 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); [String1 insertString:@"and StringEnd", atIndex:[String1 length]]; // 在可变字符串的最后插入 //----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); //----查找----- NSRange subRange = [String1 rangeOfString:@"is a"]; // 如果没查找到,则 (subRange.location == NSNotFound)为真。 //----按照所给出的范围替换的原有的字符----- //-setString: NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"]; [String1 replaceCharactersInRange:NSMakeRange(0, 4) withString:@"That"]; // 用于NSMutableString NSLog(@"String1:%@",String1); //----在给定的范围内查找并替换----- - (NSUInteger)replaceOccurrencesOfString:(NSString *)target withString:(NSString *)replacement options:(NSStringCompareOptions)opts range:(NSRange)searchRange //----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给定的字符串 - (NSRange) rangeOfString: (NSString *) aString,这一点前面在串中搜索子串用到过 NSRange subRange; subRange = [string1 rangeOfString:@"string A"]; //查找字符串string1中是否包含“string A”。返回NSRange类型。 if(subRange.location == NSNotFound) NSLog(@"String not found "); else NSLog(@"string is at index %lu, length is %lu", subRange.location, subRange.length); //NSDate //NSCalendarDate //NSCalendarDate对象包含了日期和时间、时区以及一个带有格式的字符串,它从NSDate继承而来。 //NSCalendarDate对象是immutable的,一旦被创建,无法修改其中的时间和日期,当然可以修改那个带格式的字符串和时区。 //以下是常用方法: +(id)calendarDate; //创建当前日期和时间以及默认格式的NSCalendarDate对象,时区为机器设置好的时区。 +(id)dateWithYear:(int)year month:(unsigned)month day:(unsigned)day hour:(unsigned)hour minute:(unsigned)minute second:(unsigned)second timeZone:(NSTimeZone *)aTimeZone -(int)dayOfCommonEra; //得到从公元1年算起,有多少天 -(int)dayOfMonth; //返回是月的第几天(1-31) -(int)dayOfWeek; //返回是周的第几天 (0-6) -(int)dayOfYear; //返回是年的第几天(1-366) -(int)hourOfDay; // 返回是日的第几个小时(0-23) -(void)setCalendarFormate:(NSString *)format //--------创建NSCalendarDate对象-------- NSCalendarDate *now; now = [NSCalendarDate calendarDate]; NSTimeZone *pacific = [NSTimeZone timeZoneWithName:@"PST"]; NSCalendarDate *hotTime = [NSCalendarDate dateWithYear:2011 month:2 day:3 hour:14 minute:0 second:0 timeZone:pacific]; //NSData //使用文件时,需要频繁地将数据读入一个临时存储区,它通常成为缓冲区。 //NSData类提供了一种简单的方式,它用来设置缓冲区、将文件的内容读入缓冲区,或将缓冲区的内容写到一个文件。 //对于32位应用程序,NSDATA缓存区最多可以存储2GB的数据。 //我们既可定义不变缓冲区(NSData类),也可定义可变的缓冲区(NSMutableData类)。 //下面代码展示了如何将文件的内容读入内存缓冲区,然后再将缓冲区的内容写入到另一个文件中。 NSData *fileData;NSFileManager *fileManager = [[NSFileManager alloc]init];fileData = [fileManager contentsAtPath:path]; [fileManager createFileAtPath:path2 contents:fileData attributes:nil]; //采用默认的属性值 //类型转换 NSData -> NSString: NSString *strData = [[NSString alloc]initWithData:fileData encoding:NSASCIIStringEncoding]; //类型转换 NSString -> NSDat