NSString、NSMutableString基本使用

郝萌主倾心贡献。尊重作者的劳动成果，请勿转载。假设文章对您有所帮助。欢迎给作者捐赠，支持郝萌主。捐赠数额任意。重在心意^_^ 我要捐赠: 点击捐赠Cocos2d-X源代码下载：点我传送游戏官方下载：http://dwz.cn/RwTjl游戏视频预览：http://dwz.cn/RzHHd游戏开发博客：http://dwz.cn/RzJzI游戏源代码传送：http://dwz.cn/Nret1NSString事实上是一个对象类型。NSString是NSObject（Cocoa Foundation的基础对象）的子类一、NSString的创建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);NSString *astring = [[NSString alloc] init];NSLog(@"0x%.8x", astring);astring=@"This is a String!";NSLog(@"0x%.8x", astring);[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、创建暂时字符串NSString *astring;astring = [NSString stringWithCString:"This is a temporary string"];NSLog(@"astring:%@",astring);7、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];  8、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];二、字符串的比較1、用C比較: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)    NSString *astring01 = @"This is a String!";NSString *astring02 = @"This is a String!";    BOOL result = [astring01 compare:astring02] = = NSOrderedSame;    NSLog(@"result:%d",result);    //NSOrderedSame推断两者内容是否同样NSString *astring01 = @"This is a String!";NSString *astring02 = @"this is a String!";BOOL result = [astring01 compare:astring02] = = NSOrderedAscending;    NSLog(@"result:%d",result);//NSOrderedAscending推断两对象值的大小(按字母顺序进行比較。astring02大于astring01为真)不考虑大写和小写比較字符串NSString *astring01 = @"this is a String!";NSString *astring02 = @"This is a String!";BOOL result = [astring01 caseInsensitiveCompare:astring02] = = NSOrderedSame;    NSLog(@"result:%d",result);     //NSOrderedDescending推断两对象值的大小(按字母顺序进行比較，astring02小于astring01为真)不考虑大写和小写比較字符串2NSString *astring01 = @"this is a String!";NSString *astring02 = @"This is a String!";BOOL result = [astring01 compare:astring02options:NSCaseInsensitiveSearch | NSNumericSearch] = = NSOrderedSame;    NSLog(@"result:%d",result);     P.S : NSCaseInsensitiveSearch:不区分大写和小写比較 NSLiteralSearch:进行全然比較。区分大写和小写 NSNumericSearch:比較字符串的字符个数，而不是字符值。三、改写字符串NSString *string1 = @"A String"; NSString *string2 = @"String"; NSLog(@"string1:%@",[string1 uppercaseString]);//大写NSLog(@"string2:%@",[string2 lowercaseString]);//小写NSLog(@"string2:%@",[string2 capitalizedString]);//首字母大小四、搜索字符串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];五、字符串的截取1.-substringToIndex: 从字符串的开头一直截取到指定的位置，但不包含该位置的字符NSString *string1 = @"This is a string";NSString *string2 = [string1 substringToIndex:3];NSLog(@"string2:%@",string2);2.-substringFromIndex: 以指定位置開始（包含指定位置的字符），并包含之后的所有字符NSString *string1 = @"This is a string";NSString *string2 = [string1 substringFromIndex:3];NSLog(@"string2:%@",string2);3.-substringWithRange: //依照所给出的位置，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.截取NSString最后一位符号后的东西方法1.NSString *str = @"/Users/yangiori/Library/Application Support/iPhone Simulator/5.1/Applicati*****/8724956B-407E-4ACD-BBA6-95C7D033C33D/Documents/content/chapters/8";NSString *temp1 = [[str componentsSeparatedByString:@"/"] lastObject];NSLog(@"%@",temp1);结果：8方法2.NSString *str = @"/Users/yangiori/Library/Application Support/iPhone Simulator/5.1/Applicati*****/8724956B-407E-4ACD-BBA6-95C7D033C33D/Documents/content/chapters/8";NSString *temp2 = [str substringFromIndex:[str length]-1];NSLog(@"%@",temp2);结果：85.从指定位置截取字符串NSString * str =[NSString stringWithFormat:@"********************Documents/image%i.jpg",2];NSRange range = [str rangeOfString:@"Documents"]; NSString * result = [str substringFromIndex:range.location]; NSLog(@"%@",result);六、其他操作1.扩展路径NSString *Path = @"~/NSData.txt";NSString *absolutePath = [Path stringByExpandingTildeInPath];NSLog(@"absolutePath:%@",absolutePath);NSLog(@"Path:%@",[absolutePath stringByAbbreviatingWithTildeInPath]);2.文件扩展名NSString *Path = @"~/NSData.txt";NSLog(@"Extension:%@",[Path pathExtension]);NSMutableString基本使用方法1.给字符串分配容量stringWithCapacity:NSMutableString *String;String = [NSMutableString stringWithCapacity:40];2.在已有字符串后面加入字符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);3.在已有字符串中依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);4.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);5.将已有的空符串换成其他的字符串-setString:NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];[String1 setString:@"Hello Word!"];NSLog(@"String1:%@",String1);6.依照所给出的范围。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);7.推断字符串内是否还包含别的字符串(前缀。后缀)01：检查字符串是否以还有一个字符串开头- (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他字符串 - (NSRange) rangeOfString: (NSString *) aString，这一点前面在串中搜索子串用到过;郝萌主倾心贡献。尊重作者的劳动成果，请勿转载。假设文章对您有所帮助。欢迎给作者捐赠，支持郝萌主，捐赠数额任意，重在心意^_^ 我要捐赠: 点击捐赠Cocos2d-X源代码下载：点我传送游戏官方下载：http://dwz.cn/RwTjl游戏视频预览：http://dwz.cn/RzHHd游戏开发博客：http://dwz.cn/RzJzI游戏源代码传送：http://dwz.cn/Nret1

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