ios數組基本用法和排序大全

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由於我寫的時候用到了數組的排序，發現這篇文章不錯，推薦給大家。

文章來自：http://blog.csdn.net/daiyelang/article/details/18726947

// 建立一個空的數組  NSArray *array = [NSArray array];      // 建立有1個元素的數組  array = [NSArray arrayWithObject:@"123"];  // 建立有多個元素的數組  array = [NSArray arrayWithObjects:@"a", @"b", @"c", nil nil];  NSArray *array3 = [array arrayByAddingObjectsFromArray:[NSArray arrayWithObjects:@"4", @"5", nil nil]];  NSArray *array4 = [NSArray arrayWithObjects:@"1", @"2", @"3", @"4", nil nil];  NSRange range = NSMakeRange(1, 2);  NSArray *array5 = [array4 subarrayWithRange:range];  

2.數組的一些基本方法

int count = [array count];//個數  // 判斷是否包含了某個元素  if ([array containsObject:@"a"]) {      NSLog(@"包含了字串a");  }  NSString *last = [array lastObject];最後一個元素  NSString *str = [array objectAtIndex:1];根據索引擷取數組中的元素  int index = [array indexOfObject:@"c"];擷取指定元素的索引  // 讓數組裡面的所有對象都調用test方法，123為參數  NSArray *array = [NSArray arrayWithObjects:stu1, stu2, stu3, nil nil];  [array makeObjectsPerformSelector:@selector(test2:) withObject:@"123"];  NSArray *array = [NSArray arrayWithObjects:@"1", @"2", @"3", @"4", nil nil];  // 1-2-3-4  // 利用分隔字元-拼接所有的數組元素  NSString *str = [array componentsJoinedByString:@"-"];  // 將一個數組寫入檔案（產生的是一個xml檔案）  NSString *path = @"/Users/apple/Desktop/array.xml";  [array writeToFile:path atomically:YES];  path = @"/Users/apple/Desktop/array.txt";  // 從檔案中讀取數組內容（檔案有嚴格的格式要求）  NSArray *array2 = [NSArray arrayWithContentsOfFile:path];  

3.遍曆數組

#pragma mark 遍曆數組1  void arrayFor1() {      NSArray *array = [NSArray arrayWithObjects:stu1, @"1", @"2", @"3", nil nil];      int count = array.count;      for (int i = 0; i<count; i++) {          id obj = [array objectAtIndex:i];      }  }    #pragma mark 遍曆數組2 快速遍曆  void arrayFor2() {      Student *stu1 = [Student student];      NSArray *array = [NSArray arrayWithObjects:stu1, @"1", @"2", @"3", nil nil];      int i =0;      for (id obj in array) {          NSLog(@"%i-%@", i, obj);          i++;      }  }    #pragma mark 遍曆數組3  void arrayFor3() {      Student *stu1 = [Student student];      NSArray *array = [NSArray arrayWithObjects:stu1, @"1", @"2", @"3", nil nil];      [array enumerateObjectsUsingBlock:       ^(id obj, NSUInteger idx, BOOLBOOL *stop) {          NSLog(@"%i-%@", idx, obj);           // 如果索引為1，就停止遍曆           if (idx == 1) {               // 利用指標修改外面BOOL變數的值               *stop = YES;           }      }];  }    #pragma mark 遍曆數組4  void arrayFor4() {      Student *stu1 = [Student student];      NSArray *array = [NSArray arrayWithObjects:stu1, @"1", @"2", @"3", nil nil];      // 擷取數組的迭代器      // NSEnumerator *enumerator = [array objectEnumerator];      // 反序迭代器（從尾部開始遍曆元素）      NSEnumerator *enumerator = [array reverseObjectEnumerator];      // allObjects是取出沒有被遍曆過的對象      NSArray *array2 = [enumerator allObjects];      NSLog(@"array2:%@", array2);      // 擷取下一個需要遍曆的元素      id obj = nil;      while (obj = [enumerator nextObject]) {          NSLog(@"obj=%@", obj);      }  }  

4.數組排序

#pragma mark 數組排序1  void arraySort1() {      NSArray *array = [NSArray arrayWithObjects:@"2", @"3", @"1", @"4", nil nil];            // 返回一個排好序的數組，原來數組的元素順序不會改變      // 指定元素的比較方法：compare:      NSArray *array2 = [array sortedArrayUsingSelector:@selector(compare:)];      NSLog(@"array2:%@", array2);  }    #pragma mark 數組排序2  void arraySort2() {      Student *stu1 = [Student studentWithFirstname:@"MingJie" lastname:@"Li"];      Student *stu2 = [Student studentWithFirstname:@"LongHu" lastname:@"Huang"];      Student *stu3 = [Student studentWithFirstname:@"LianJie" lastname:@"Li"];      Student *stu4 = [Student studentWithFirstname:@"Jian" lastname:@"Xiao"];      NSArray *array = [NSArray arrayWithObjects:stu1,stu2,stu3, stu4, nil nil];      // 指定排序的比較方法      NSArray *array2 = [array sortedArrayUsingSelector:@selector(compareStudent:)];      NSLog(@"array2:%@", array2);  }  - (NSComparisonResult)compareStudent:(Student *)stu {      // 先按照姓排序      NSComparisonResult result = [self.lastname compare:stu.lastname];      // 如果有相同的姓，就比較名字      if (result == NSOrderedSame) {          result = [self.firstname compare:stu.firstname];      }      return result;  }    #pragma mark 數組排序3  void arraySort3() {      Student *stu1 = [Student studentWithFirstname:@"MingJie" lastname:@"Li"];      Student *stu2 = [Student studentWithFirstname:@"LongHu" lastname:@"Huang"];      Student *stu3 = [Student studentWithFirstname:@"LianJie" lastname:@"Li"];      Student *stu4 = [Student studentWithFirstname:@"Jian" lastname:@"Xiao"];      NSArray *array = [NSArray arrayWithObjects:stu1,stu2,stu3, stu4, nil nil];            // 利用block進行排序      NSArray *array2 = [array sortedArrayUsingComparator:       ^NSComparisonResult(Student *obj1, Student *obj2) {           // 先按照姓排序           NSComparisonResult result = [obj1.lastname compare:obj2.lastname];           // 如果有相同的姓，就比較名字           if (result == NSOrderedSame) {               result = [obj1.firstname compare:obj2.firstname];           }                      return result;      }];            NSLog(@"array2:%@", array2);  }    #pragma mark 數組排序4-進階排序  void arraySort4() {      Student *stu1 = [Student studentWithFirstname:@"MingJie" lastname:@"Li" bookName:@"book1"];      Student *stu2 = [Student studentWithFirstname:@"LongHu" lastname:@"Huang" bookName:@"book2"];      Student *stu3 = [Student studentWithFirstname:@"LianJie" lastname:@"Li" bookName:@"book2"];      Student *stu4 = [Student studentWithFirstname:@"Jian" lastname:@"Xiao" bookName:@"book1"];      NSArray *array = [NSArray arrayWithObjects:stu1,stu2,stu3, stu4, nil nil];            // 1.先按照書名進行排序      // 這裡的key寫的是@property的名稱      NSSortDescriptor *bookNameDesc = [NSSortDescriptor sortDescriptorWithKey:@"book.name" ascending:YES];      // 2.再按照姓進行排序      NSSortDescriptor *lastnameDesc = [NSSortDescriptor sortDescriptorWithKey:@"lastname" ascending:YES];      // 3.再按照名進行排序      NSSortDescriptor *firstnameDesc = [NSSortDescriptor sortDescriptorWithKey:@"firstname" ascending:YES];      // 按順序添加排序描述器      NSArray *descs = [NSArray arrayWithObjects:bookNameDesc, lastnameDesc, firstnameDesc, nil nil];            NSArray *array2 = [array sortedArrayUsingDescriptors:descs];            NSLog(@"array2:%@", array2);  }  

 

ios數組基本用法和排序大全