14.NSString/NSMutableString用法总结

NSString总结

初始化与赋值

    //初始化    NSString *str = @"普通初始化";    NSString *str1 = [[NSString alloc] initWithString: @"初始化"];     //赋值    NSString *str = [NSString stringWithFormat: @"%d",int/NSInteger/BOOL/float/double...];    NSString *str = [NSString stringWithString: @"字符串"]; 

数据类型转换成NSString

    //NSData 转 NSString    NSString *str = [[NSString alloc] initWithData:NSData() encoding: NSASCIIStringEncoding];    //char 转 NSString    NSString *str=[NSString stringWithCString: char()  encoding: NSUTF8StringEncoding];     //字符串转换为utf-8格式 参数为char*类型    NSString *str3 = [NSString stringWithUTF8String:"字符串转换utf-8格式"];    //URL 转 NSString    NSString *str1 = [URL() absoluteString];    //int float BOOL double NSInteger 转 NSString    NSString *str = [NSString stringWithFormat:@"%d",value];        //其他转换方式    NSString *tmp [double()    doubleValue];  //double    NSString *tmp [float()     floatValue];   //float    NSString *tmp [NSInteger() integerValue]; //NSInteger    NSString *tmp [int()       intvalue];     //int    NSString *tmp [BOOL()      boolValue];    //BOOL    

截取和处理字符串

    //获取字符串长度    NSUInteger length = [NSString() length];    //获取索引字符    unichar ch = [NSString() characterAtIndex: int()];    //索引到结尾    NSString *str = [NSString() substringFromIndex: int()];    //开始到索引    NSString *str = [NSString() substringToIndex: int()];    //获取X到Y的字符串(X>Y)    NSString *str3 = [NSString() substringWithRange: NSMakeRange(X, Y)];    //拼接字符串    NSString *str = [@"第一段字符串" stringByAppendingString: @"第二段字符串"];    //特定范围插入字符串(X为索引，Y为需要覆盖的字符数量)    NSString *tmp = [@"被插入的字符串" stringByReplacingOccurrencesOfString: NSMakeRange(X, Y) withString: @"插入的字符串"];    //查找指定字符串，然后替换字符串    NSString *tmp =[@"被替换字符串" stringByReplacingOccurrencesOfString: @"指定字符串" withString: @"替换的字符串"];    //查找指定字符串，并显示该字符串在被查找字符串的位置(打印range为1,)    NSRange range = [@"被查找的字符串" rangeOfString: @"查找的字符串"];    NSLog(@"str2在str1的位置：%lu，str2的长度:%lu",            (unsigned long)range.location, (unsigned long)range.length);

文件读写

    //YES:数组写入临时文件, 写入成功，再写入目标文件。    //NO：数组直接被写入目标文件    NSString *path = [[NSString alloc] initWithString: "文件名加格式"];    [NSString() writeToFile path ]    //从文件中读取字符串    NSString *str = [[NSString alloc] initWithContentsOfFile: path];  

字符串判断

    //是否为空    NSString() == nil    NSString().length == 0    //判断开头字符串是否以"@"字符串"为开头    [NSString() hasPrefix: @"字符串"];    //判断结尾字符串是否以"@"字符串"为结尾    [NSString() hasSuffix: @"字符串"];    //判断两个字符是否相同    BOOL tmp = [@"字符串" isEqualToString @"字符串"];    BOOL tmp = [@"字符串" compare: @"字符串"] == NSOrderedSame;     //判断两对象值的大小(按字母顺序进行比较，str2 > str1为真)    BOOL tmp = [str1 compare: str2] == NSOrderedAscending;    //判断两对象值的大小(按字母顺序进行比较，str2 < str1为真)    BOOL tmp = [str1 compare: str2] == NSOrderedDescending;     //不区分大小写，进行比较    //判断两对象值的大小(按字母顺序进行比较，str2 < str1为真)     BOOL tmp = [str1 caseInsensitiveCompare: str2] == NSOrderedDescending ;    //NSCaseInsensitiveSearch：不区分大小写    //NSLiteralSearch：        区分大小写    //NSNumericSearch:         比较字符个数    BOOL result = [str1 compare: str2 options: NSCaseInsensitiveSearch | NSNumericSearch] == NSOrderedSame;    //判断两对象值的大小(按字母顺序进行比较，str2 > str1为真)    BOOL tmp = [str1 caseInsensitiveCompare: str2] == NSOrderedAscending  ;

字符串字母转换

    //每个首字母大写，其余字母小写    NSString *tmp [@"字符串" capitalizedString];    //转换成小写    NSString *tmp [@"字符串" lowercaseString];    //转换成大写    NSString *tmp [@"字符串" uppercaseString];

NSMutableString总结

    //初始化    NSMutableString *str = [[NSMutableString alloc] initWithString: @"字符串"];    //赋值    NSMutableString *str = [NSMutableString stringWithString: @"字符串"];      [str setString:@"字符串"];    //删除指定字符串    NSMutableString *tmp = [NSMutableString() deleteCharactersInRange: [NSMutableString() rangeOfString: @"字符串"]];     //往尾部添加字符串    NSMutableString *tmp = NSMutableString() appendFormat: @"字符串"];     //在指定位置插入字符串    NSMutableString *tmp = [NSMutableString() insertString:@"插入的字符串" atIndex: int()];    //替换指定字符串(X > Y)    NSMutableString *tmp = [NSMutableString() replaceCharactersInRange:NSMakeRange(X, Y) withString:@"字符串"];