ios - NSDictionary 中值的总和

Question

我正在寻找一种有效且简单的方法来对 NSDictionary 中的所有值求和。

例如，如果我有像这样的 NSDictionary:

NSDictionary * first = @{@"A": [NSNumber numberWithInt:1],
                         @"B": [NSNumber numberWithInt:2],
                         @"C": [NSNumber numberWithInt:3],
                         @"D": [NSNumber numberWithInt:4]};

NSDictionary * second = @{@"A": [NSNumber numberWithInt:1],
                         @"B": [NSNumber numberWithInt:2],
                         @"C": [NSNumber numberWithInt:3],
                         @"D": [NSNumber numberWithInt:4]};

我想要一个 NSDictyonary

NSDictionary * sum = @{@"A": [NSNumber numberWithInt:2],
                         @"B": [NSNumber numberWithInt:4],
                         @"C": [NSNumber numberWithInt:6],
                         @"D": [NSNumber numberWithInt:8]};

Answer 1

NSDictionary * first = @{@"A": [NSNumber numberWithInt:1],
                         @"B": [NSNumber numberWithInt:2],
                         @"C": [NSNumber numberWithInt:3],
                         @"D": [NSNumber numberWithInt:4]};

NSDictionary * second = @{@"A": [NSNumber numberWithInt:1],
                          @"B": [NSNumber numberWithInt:2],
                          @"C": [NSNumber numberWithInt:3],
                          @"D": [NSNumber numberWithInt:4]};
NSMutableDictionary *Third=[[NSMutableDictionary alloc]init];
for (NSString* key in [first allKeys]) {
    NSLog(@"%@",key);

    int a=[[first objectForKey:key]integerValue];
    int b=[[second objectForKey:key]integerValue];

    int c= a+b;

    [Third setObject:[NSNumber numberWithInt:c]  forKey:key];

    }

NSLog(@"%@",Third);

更新了不同的 key

NSArray *Key_of_First=[first allKeys];
NSArray *Key_of_Second=[second allKeys];

for (int j=0; j<Key_of_First.count; j++) {

    int a=[[first objectForKey:[Key_of_First objectAtIndex:j]]integerValue];
    int b=[[second objectForKey:[Key_of_Second objectAtIndex:j]]integerValue];

    int c= a+b;

    [Third setObject:[NSNumber numberWithInt:c]  forKey:@"Your Key Name which you give"];

}

  NSLog(@"%@",Third);