NSString 對象類型
一個NSString對象可以存儲一段Unicode字符。在cocoa中躲查，所有和字符它浅、字符串相關(guān)的處理都是使用NSString來完成。
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)建一個新的字符串镣煮，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; // 給一個字符串附加一個字符串string姐霍。
- (NSString *)stringByAppendingFormat:(NSString *)string;
- (NSString *)stringByDeletingPathComponent;
-----創(chuàng)建字符串的方法-----
//1、創(chuàng)建常量字符串
NSString *astring = @"This is a String!";
//2典唇、先創(chuàng)建一個空的字符串镊折，然后賦值；
// alloc和init組合則適合在函數(shù)之間傳遞參數(shù)
NSString *astring = [[NSString alloc] init];
astring = @"This is a String!";
NSLog(@"astring:%@",astring);
//3介衔、在以上方法中恨胚，提升速度:initWithString方法
NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];
NSLog(@"astring:%@",astring);
//4、創(chuàng)建臨時字符串
NSString *astring;
astring = [NSString stringWithCString:"This is a temporary string"];
NSLog(@"astring:%@",astring);
// OR
NSString * scriptString = [NSString stringWithString:@" tell application \"Mail\"\r"];
//5炎咖、創(chuàng)建格式化字符串:占位符（由一個%加一個字符組成）
int i = 1;
int j = 2;
NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@"%d.This is %i string!",i,j]];
NSLog(@"astring:%@",astring);
-----從文件讀取字符串-----
NSString *path = @"astring.text";
NSString *astring = [[NSString alloc] initWithContentsOfFile:path];
NSLog(@"astring:%@",astring);
-----寫字符串到文件----
NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];
NSLog(@"astring:%@",astring);
NSString *path = @"astring.text";
[astring writeToFile: path atomically: YES];
-----比較兩個字符串-----
//1赃泡、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乘盼、compare方法(comparer返回的三種值：NSOrderedSame升熊，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 判斷兩對象值的大小(按字母順序進(jìn)行比較蹦肴，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 判斷兩對象值的大小(按字母順序進(jìn)行比較僚碎，astring02小于astring01為真)
//4猴娩、不考慮大小寫比較字符串1
NSString *astring01 = @"this is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 caseInsensitiveCompare:astring02] = = NSOrderedSame;
NSLog(@"result:%d",result);
//NSOrderedDescending判斷兩對象值的大小(按字母順序進(jìn)行比較阴幌，astring02小于astring01為真)
//5、不考慮大小寫比較字符串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)分大小寫比較 NSLiteralSearch:進(jìn)行完全比較卷中，區(qū)分大小寫 NSNumericSearch:比較字符串的字符個數(shù)矛双，而不是字符值。
-----改變字符串的大小寫-----
NSString *string1 = @"A String";
NSString *string2 = @"String";
NSLog(@"string1:%@",[string1 uppercaseString]);//uppercaseString返回轉(zhuǎn)換為大寫的字符串
NSLog(@"string2:%@",[string2 lowercaseString]);//lowercaseString返回轉(zhuǎn)換為小寫的字符串
NSLog(@"string2:%@",[string2 capitalizedString]);//capitalizedString返回每個單詞首字母大寫的字符串
-----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);
-----抽取子串 -----
//1蟆豫、-substringToIndex: 從字符串的開頭一直截取到指定的位置议忽，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、-substringFromIndex: 以指定位置開始（包括指定位置的字符）十减，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栈幸、-substringWithRange: //按照所給出的位置，長度帮辟，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速址、快速枚舉
for(NSString *filename in direnum) {
if([[filename pathExtension] isEqualToString:@"jpg"]){
[files addObject:filename];
}
}
NSLog(@"files:%@",files);
//5、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);
-----切分?jǐn)?shù)組-----
//1由驹、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);
//2芍锚、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，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"]; // 如果沒查找到，則 （subRange.location == NSNotFound）為真并炮。
----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(前綴默刚，后綴)-----
//01： 檢查字符串是否以另一個字符串開頭- (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，這一點(diǎn)前面在串中搜索子串用到過
NSRange subRange;
subRange = [string1 rangeOfString:@"string A"]; //查找字符串string1中是否包含“string A”逃魄。返回NSRange類型荤西。
if(subRange.location == NSNotFound)
NSLog(@"String not found ");
else NSLog(@"string is at index %lu, length is %lu", subRange.location, subRange.length);
NSNumber
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，形成一個對象伍俘，這樣就可以給其發(fā)送消息皂冰，裝入NSArray中等等。
NSNumber * intNumber=[NSNumber numberWithInt：100]养篓；
NSNumber *floatNumber=[NSNUmber numberWithFloat:100.00];
int i=[intNumber intValue]秃流；
if([intNumber isEqualToNumber:floatNumber]) ....
NSNumber繼承NSObject ，可以使用比較 compare： isEqual等消息
int i = 1 ;
long l = 22222;
NSNumber *number1 = [[NSNumber alloc]initWithInt:i];
NSLog(@"%@",number1);
NSNumber *number2 = [[NSNumber alloc]initWithLong:l];
NSLog(@"%@",number2);
NSNumber是將基本的類型轉(zhuǎn)換為對象類型
int a1 = [number1 intValue];//將NSNumber類型轉(zhuǎn)換成int類型
NSString *string2 = @"123";
NSLog(@"%d", [string2 intValue]);將字符串中的數(shù)字轉(zhuǎn)換成int類型并輸出
將NSNumber轉(zhuǎn)換成字符串
[number2 stringValue];
NSLog(@"%@",[number2 stringValue]);
// NSMutableString *a = [NSMutableString stringWithString:@"i love you"];
// NSString *a1 = [a capitalizedString];
// NSLog(@"%@",a1);
//
// NSString *a2 = [NSString stringWithFormat:@"20|[http://www.baidu.com](http://www.baidu.com)"];
// NSString *a3 = [a2 substringToIndex:2];
// NSString *a4 = [a2 substringFromIndex:3];
// NSLog(@"%@\n%@",a3,a4);
// NSArray *b = [a2 componentsSeparatedByString:@"|"];
// NSString *c1 = [b objectAtIndex:0];
// NSString *c2 = [b objectAtIndex:1];
// NSLog(@"%@ %@",c1,c2);
int a = 1 ;
float b = 2 ;
BOOL flag = 1 ;
NSRange c = NSMakeRange(1, 1);
NSNumber *d1 = [[NSNumber alloc]initWithInt:a];
NSNumber *d2 = [[NSNumber alloc]initWithFloat:b];
NSNumber *d3 = [[NSNumber alloc]initWithBool:flag];
NSValue *d4 = [NSValue valueWithRange:c];
NSMutableArray *aa = [NSMutableArray arrayWithObjects:d1,d2,d3,d4, nil ];
for (int i = 0;i < [aa count];i ++)
{
NSLog(@"%@",aa[i]);
// NSLog(@"%@",[mularr objectAtIndex:i]);
}
