OC中NSString 的常用方法
//字符串的截取 NSString *str = @"123456789"; NSLog(@"%@",[str substringFromIndex:3]); NSLog(@"%@",[str substringToIndex:6]); NSLog(@"%@",[str substringWithRange:NSMakeRange(3, 3)]); //用指定字符串分割字符串，返回一个数组 NSArray *array = [@"1,2,3,4,5,6" componentsSeparatedByString:@","]; NSLog(@"%@",array); //将数组中的字符串组合成一个文件路径 NSMutableArray *components = [NSMutableArray array]; [components addObject:@"Users"]; [components addObject:@"CentralPerk"]; [components addObject:@"Desktop"]; NSString *path = [NSString pathWithComponents:components]; NSLog(@"%@",path); //Users/CentralPerk/Desktop //将一个路径分割成一个数组 NSArray *array1 = [path pathComponents]; NSLog(@"%@",array1); //判断是否为绝对路径(依据：是否以'/'开始) path = @"/Users/CentralPerk/Desktop"; NSLog(@"%i",[path isAbsolutePath]); //获取最后一个目录 NSLog(@"%@",[path lastPathComponent]); //删除最后一个目录 NSLog(@"%@",[path stringByDeletingLastPathComponent]); //拼接一个目录 NSLog(@"%@",[path stringByAppendingPathComponent:@"aaa"]); ///Users/CentralPerk/Desktop/aaa NSLog(@"%@",[path stringByAppendingString:@"aaa"]); ///Users/CentralPerk/Desktopaaa NSLog(@"%@",[path stringByAppendingFormat:@"%@%@",@"b",@"c"]); ///Users/CentralPerk/Desktopbc //拓展名出来 //获取拓展名,不带. NSString *str2 = @"Users/CentralPerk/Desktop/test.txt"; NSLog(@"%@",[str2 pathExtension]); //添加拓展名,不需要带. NSLog(@"%@",[str2 stringByAppendingPathExtension:@"mp3"]); //删除拓展名,带.一块删除 NSLog(@"%@",[str2 stringByDeletingPathExtension]); //字符串转为 int double float NSString *str3 = @"123"; NSLog(@"%i",[str3 intValue]); NSLog(@"%zi",[str3 length]); //取出指定位置的字符 unichar c = [str3 characterAtIndex:2]; NSLog(@"%c",c); //转为C语言的字符串 const char *s = [str3 UTF8String]; NSLog(@"%s",s);
