In [this answer](https://stackoverflow.com/a/20243180/34088), 

```
awk '$2=="no"{$3="N/A"}1' file

```

was accepted. Note the `1` at the end of the AWK script. In the comments, the author of the answer said

> 
> [1 is] a cryptic way to display the current line.
> 
> 
> 

I'm puzzled. How does that work?