NSString类的常用方法 - 黑马程序员技术交流社区

- NSString *str1 = @"BeiJing";
- NSString *str2 = @"beijing";
-
- //全部转为大写
- NSLog(@"%@",[str1 uppercaseString]);
-
- //全部转为小写
- NSLog(@"%@",[str1 lowercaseString]);
-
- //首字母大写
- NSLog(@"%@",[str1 capitalizedString]);
-
- //比较两个字符串内容是否相同
- BOOL b =[str1 isEqualToString:str2];
-
- //两个字符串内容比较
- //NSOrderedAscending 右边 > 左边
- //NSOrderedSame 内容相同
- //NSOrderedDescending 左边 > 右边
- NSComparisonResult result = [str1 compare:str2];
- if (result == NSOrderedAscending) {
- NSLog(@"右边 > 左边");
- }else if(result == NSOrderedSame){
- NSLog(@"内容相同");
- }else if (result == NSOrderedDescending){
- NSLog(@"左边 > 右边");
- }
-
- //忽略大小写进行比较，返回值与compare一样
- result = [str1 caseInsensitiveCompare:str2];
- if (result == NSOrderedAscending) {
- NSLog(@"右边 > 左边");
- }else if(result == NSOrderedSame){
- NSLog(@"内容相同");
- }else if (result == NSOrderedDescending){
- NSLog(@"左边 > 右边");
- }
-
- //判断字符串是否以指定字符串开头
- [str1 hasPrefix:@"aaa"];
- //判断字符串是否以指定字符串结尾
- [str1 hasSuffix:@"aaa"];
-
- //判断字符串是否包含指定字符串，返回位置和长度
- NSRange range = [@"123456" rangeOfString:@"456"];
- NSLog(@"%@", NSStringFromRange(range));
-
- //反向搜索
- range = [@"123456456qweasasd456" rangeOfString:@"456" options:NSBackwardsSearch];
- NSLog(@"%@",NSStringFromRange(range));
-
- //指定范围进行搜索
- range = NSMakeRange(0, 9);
- range = [@"123456456qweasasd456" rangeOfString:@"456" options:NSBackwardsSearch range:range];
- NSLog(@"%@",NSStringFromRange(range));
[cpp] view plaincopy
- <pre name="code" class="cpp">//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);
- </pre><br><br>

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