NSNumber

• (NSNumber *)numberWithInt:(int)value;
• (NSNumber *)numberWithDouble:(double)value;

• (int)intValue;
• (double)doubleValue;
  NSNumber可以將基本數(shù)據(jù)類型包裝起來(lái)，形成一個(gè)對(duì)象憋活，這樣就可以給其發(fā)送消息，裝入NSArray中等等虱黄。

NSNumber * intNumber=[NSNumber numberWithInt：100]悦即；
NSNumber *floatNumber=[NSNUmber numberWithFloat:100.00];
int i=[intNumber intValue]；
if([intNumber isEqualToNumber:floatNumber]) ....
NSNumber繼承NSObject 橱乱，可以使用比較 compare： isEqual等消息
NSString

一個(gè)NSString對(duì)象可以存儲(chǔ)一段Unicode字符辜梳。在cocoa中，所有和字符泳叠、字符串相關(guān)的處理都是使用NSString來(lái)完成作瞄。

NSObject -> NSString // NSString繼承自NSObject
+(id) stringWithContentsOfFile:path encoding:enc error:err;
+(id) stringWithContentsOfURL:url encoding:enc error:err;
+(id) stringWithString:nsstring; //創(chuàng)建一個(gè)新的字符串，并將其設(shè)置為nsstring
-(id)initWithFormat:(NSString *)format, ... ;
-(id)initWithString:nsstring; //將分配的字符串設(shè)置為nsstring

• (BOOL)isEqualToString:(NSString *)string;
• (BOOL)hasPrefix:(NSString *)string;
• (int)intValue;
• (double)doubleValue;
• (NSString *)stringByAppendingString:(NSString *)string; // 給一個(gè)字符串附加一個(gè)字符串string危纫。
• (NSString *)stringByAppendingFormat:(NSString *)string;
• (NSString *)stringByDeletingPathComponent;

-----創(chuàng)建字符串的方法-----
//1宗挥、創(chuàng)建常量字符串
NSString *astring = @"This is a String!";
//2、先創(chuàng)建一個(gè)空的字符串种蝶，然后賦值契耿；
// alloc和init組合則適合在函數(shù)之間傳遞參數(shù)，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螃征、在以上方法中搪桂，提升速度:initWithString方法

    NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];
    NSLog(@"astring:%@",astring);
    [astring release];

//4、創(chuàng)建臨時(shí)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盯滚、創(chuàng)建格式化字符串:占位符（由一個(gè)%加一個(gè)字符組成）

    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];
-----從文件讀取字符串-----
    NSString *path = @"astring.text";
    NSString *astring = [[NSString alloc] initWithContentsOfFile:path];
    NSLog(@"astring:%@",astring);
    [astring release];
-----寫(xiě)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];   

-----比較兩個(gè)字符串-----
//1踢械、用C比較:strcmp函數(shù)

    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魄藕、compare方法(comparer返回的三種值：NSOrderedSame内列，NSOrderedAscending，NSOrderedDescending)

    NSString *astring01 = @"This is a String!";
    NSString *astring02 = @"This is a String!";   
    BOOL result = [astring01 compare:astring02] = = NSOrderedSame;   //NSOrderedSame 判斷兩者內(nèi)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 判斷兩對(duì)象值的大小(按字母順序進(jìn)行比較泼疑，astring02大于astring01為真)
    NSString *astring01 = @"this is a String!";
    NSString *astring02 = @"This is a String!";
    BOOL result = [astring01 compare:astring02] = = NSOrderedDescending;   
    NSLog(@"result:%d",result);     
    //NSOrderedDescending 判斷兩對(duì)象值的大小(按字母順序進(jìn)行比較德绿，astring02小于astring01為真)

//4荷荤、不考慮大小寫(xiě)比較字符串1

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

//NSOrderedDescending判斷兩對(duì)象值的大小(按字母順序進(jìn)行比較，astring02小于astring01為真)

//5移稳、不考慮大小寫(xiě)比較字符串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:不區(qū)分大小寫(xiě)比較 NSLiteralSearch:進(jìn)行完全比較蕴纳，區(qū)分大小寫(xiě) NSNumericSearch:比較字符串的字符個(gè)數(shù)，而不是字符值个粱。

-----改變字符串的大小寫(xiě)-----

    NSString *string1 = @"A String";
    NSString *string2 = @"String";
    NSLog(@"string1:%@",[string1 uppercaseString]);//uppercaseString返回轉(zhuǎn)換為大寫(xiě)的字符串
    NSLog(@"string2:%@",[string2 lowercaseString]);//lowercaseString返回轉(zhuǎn)換為小寫(xiě)的字符串
    NSLog(@"string2:%@",[string2 capitalizedString]);//capitalizedString返回每個(gè)單詞首字母大寫(xiě)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古毛、-substringToIndex: 從字符串的開(kāi)頭一直截取到指定的位置，但不包括該位置的字符

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

//2都许、-substringFromIndex: 以指定位置開(kāi)始（包括指定位置的字符）稻薇，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: //按照所給出的位置胶征，長(zhǎng)度塞椎，任意地從字符串中截取子串

    NSString *string1 = @"This is a string";
    NSString *string2 = [string1 substringWithRange:NSMakeRange(0, 4)];
    NSLog(@"string2:%@",string2);

//4、快速枚舉

    for(NSString *filename in direnum)    {
        if([[filename pathExtension] isEqualToString:@"jpg"]){
            [files addObject:filename];
        }
    }
    NSLog(@"files:%@",files);

//5睛低、枚舉

    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?jǐn)?shù)組-----
//1案狠、從字符串分割到數(shù)組－ componentsSeparatedByString:

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

//2、從數(shù)組合并元素到字符串- componentsJoinedByString:

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

-----從目錄搜索擴(kuò)展名為jpg的文件-----

//NSFileManager *fileManager = [NSFileManager defaultManager];
    NSString *home;
    home = @"../Users/";
    NSDirectoryEnumerator *direnum;
    direnum = [fileManager enumeratorAtPath: home];
    NSMutableArray *files = [[NSMutableArray alloc] init];
//枚舉
    NSString *filename;
    while (filename = [direnum nextObject]) {
        if([[filename pathExtension] hasSuffix:@"jpg"]){
            [files addObject:filename];
        }
    }

//擴(kuò)展路徑

    NSString *Path = @"~/NSData.txt";
    NSString *absolutePath = [Path stringByExpandingTildeInPath];
    NSLog(@"absolutePath:%@",absolutePath);
    NSLog(@"Path:%@",[absolutePath stringByAbbreviatingWithTildeInPath]);

//文件擴(kuò)展名

    NSString *Path = @"~/NSData.txt";
    NSLog(@"Extension:%@",[Path pathExtension]);

-----查找與替換-----

- (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, ...;

-----給字符串分配容量-----

    //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給出范圍刪除字符----

     //deleteCharactersInRange:
     NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
     [String1 deleteCharactersInRange:NSMakeRange(0, 5)];    // 刪除指定范圍（location=0钱雷，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給出的字符串-----

    //-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]];  //  在可變字符串的最后插入

----將已有的空符串換成其它的字符串-----

    //-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"];   // 如果沒(méi)查找到骂铁，則 （subRange.location == NSNotFound）為真。

----按照所給出的范圍替換的原有的字符-----

    //-setString:
    NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
    [String1 replaceCharactersInRange:NSMakeRange(0, 4) withString:@"That"];     // 用于NSMutableString
    NSLog(@"String1:%@",String1);

----在給定的范圍內(nèi)查找并替換-----

- (NSUInteger)replaceOccurrencesOfString:(NSString *)target withString:(NSString *)replacement options:(NSStringCompareOptions)opts range:(NSRange)searchRange

----判斷字符串內(nèi)是否還包含別的字符串(前綴罩抗，后綴)-----

//01： 檢查字符串是否以另一個(gè)字符串開(kāi)頭- (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： 查找字符串某處是否包含給定的字符串 - (NSRange) rangeOfString: (NSString *) aString拉庵，這一點(diǎn)前面在串中搜索子串用到過(guò)
NSRange subRange;
subRange = [string1 rangeOfString:@"string A"];  //查找字符串string1中是否包含“string A”。返回NSRange類型套蒂。
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對(duì)象包含了日期和時(shí)間钞支、時(shí)區(qū)以及一個(gè)帶有格式的字符串，它從NSDate繼承而來(lái)泣懊。
NSCalendarDate對(duì)象是immutable的伸辟，一旦被創(chuàng)建，無(wú)法修改其中的時(shí)間和日期馍刮，當(dāng)然可以修改那個(gè)帶格式的字符串和時(shí)區(qū)信夫。
以下是常用方法：

+(id)calendarDate;  //創(chuàng)建當(dāng)前日期和時(shí)間以及默認(rèn)格式的NSCalendarDate對(duì)象，時(shí)區(qū)為機(jī)器設(shè)置好的時(shí)區(qū)卡啰。
+(id)dateWithYear:(int)year
    month:(unsigned)month
      day:(unsigned)day 
     hour:(unsigned)hour
   minute:(unsigned)minute
   second:(unsigned)second 
 timeZone:(NSTimeZone  *)aTimeZone 
-(int)dayOfCommonEra;  //得到從公元1年算起静稻，有多少天
-(int)dayOfMonth;          //返回是月的第幾天（1-31）
-(int)dayOfWeek;          //返回是周的第幾天 （0-6）
-(int)dayOfYear;          //返回是年的第幾天（1-366）
-(int)hourOfDay;          // 返回是日的第幾個(gè)小時(shí)（0-23）
-(void)setCalendarFormate:(NSString *)format 

--------創(chuàng)建NSCalendarDate對(duì)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
使用文件時(shí)，需要頻繁地將數(shù)據(jù)讀入一個(gè)臨時(shí)存儲(chǔ)區(qū)匈辱，它通常成為緩沖區(qū)振湾。
NSData類提供了一種簡(jiǎn)單的方式，它用來(lái)設(shè)置緩沖區(qū)亡脸、將文件的內(nèi)容讀入緩沖區(qū)押搪，或?qū)⒕彌_區(qū)的內(nèi)容寫(xiě)到一個(gè)文件树酪。
對(duì)于32位應(yīng)用程序，NSDATA緩存區(qū)最多可以存儲(chǔ)2GB的數(shù)據(jù)大州。
我們既可定義不變緩沖區(qū)（NSData類）续语，也可定義可變的緩沖區(qū)（NSMutableData類）。
下面代碼展示了如何將文件的內(nèi)容讀入內(nèi)存緩沖區(qū)厦画，然后再將緩沖區(qū)的內(nèi)容寫(xiě)入到另一個(gè)文件中疮茄。

NSData *fileData;NSFileManager *fileManager = [[NSFileManager alloc]init];fileData = [fileManager contentsAtPath:path];  [fileManager createFileAtPath:path2 contents:fileData attributes:nil];   //采用默認(rèn)的屬性值
類型轉(zhuǎn)換 NSData -> NSString：
NSString *strData = [[NSString alloc]initWithData:fileData encoding:NSASCIIStringEncoding];
類型轉(zhuǎn)換 NSString -> NSData：
NSData *fileData2 = [strData dataUsingEncoding:NSUTF8StringEncoding];