Question: I have a table calculated using a df which looks like the following.

```
 Month_considered   pct `ATC Count`
   <fct>            <dbl> <fct>      
 1 Apr-17            54.9 198,337    
 2 May-17            56.4 227,681    
 3 Jun-17            58.0 251,664    
 4 Jul-17            57.7 251,934    
 5 Aug-17            55.5 259,617    
 6 Sep-17            55.7 245,588    
 7 Oct-17            56.6 247,051    
 8 Nov-17            57.6 256,375    
 9 Dec-17            56.9 277,784    
10 Jan-18            56.7 272,818  

```

Now I want to find the difference in pct between two months.So the desired output would be like

```
 Month_considered          pct 
   <fct>                   <dbl>    
 1 Apr-17-May-17            1.5    
 2 May-17-Jun-17            1.6   
 3 Jun-17-Jul-17           - 0.3  

```

How do I concatenate the first column like above. I did try using `unite` in `tidyr` but it isnt the output what I want to generate.Thank you.

Answer: 
Just wanted to clarify Aung's answer: 

`npm view react-native version` checks globally while `react-native -v` ran inside project's root folder checks version of the app itself.
Macbook M1 Chip

> 
> npm view react-native version
> 
> 
>