NSString字符串常用方法
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NSString *******************************************************************************************/ //一、NSString /*----------------创建字符串的方法----------------*/ //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、创建临时字符串 NSString *astring; astring = [NSString stringWithCString:"This is a temporary string"]; NSLog(@"astring:%@",astring); /*----------------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]; /*----------------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]; /*----------------比较两个字符串----------------*/ //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。 /*----------------改变字符串的大小写----------------*/ 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 /*----------------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 ----------------*/ //-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]); /******************************************************************************************* NSMutableString *******************************************************************************************/ /*---------------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); /*--------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); /*--------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); /*--------按照所给出的范围，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); /*-------------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 *******************************************************************************************/ /*---------------------------创建数组------------------------------*/ //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]); /*--------------------------从一个数组拷贝数据到另一数组(可变数级)----------------------------*/ //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]; /*---------------------------切分数组------------------------------*/ //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); /******************************************************************************************* NSMutableArray *******************************************************************************************/ /*---------------给数组分配容量----------------*/ //NSArray *array; array = [NSMutableArray arrayWithCapacity:20]; /*--------------在数组末尾添加对象----------------*/ //- (void) addObject: (id) anObject; //NSMutableArray *array = [NSMutableArray arrayWithObjects: @"One",@"Two",@"Three",nil]; [array addObject:@"Four"]; NSLog(@"array:%@",array); /*--------------删除数组中指定索引处对象----------------*/ //-(void) removeObjectAtIndex: (unsigned) index; //NSMutableArray *array = [NSMutableArray arrayWithObjects: @"One",@"Two",@"Three",nil]; [array removeObjectAtIndex:1]; NSLog(@"array:%@",array); /*-------------数组枚举---------------*/ //- (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); } /******************************************************************************************* NSDictionary *******************************************************************************************/ /*------------------------------------创建字典------------------------------------*/ //- (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]; /******************************************************************************************* NSMutableDictionary *******************************************************************************************/ /*------------------------------------创建可变字典------------------------------------*/ //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); /******************************************************************************************* NSValue（对任何对象进行包装） *******************************************************************************************/ /*--------------------------------将NSRect放入NSArray中------------------------------------*/ //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); /******************************************************************************************* 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]; } } //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); //} |
