# eval command

The `eval` command can be used with either table data or event data.If used with event data the new field that is created won't be shown, because the event tab only shows the event data as a whole. Duh.

To show the new field that you have created then you will have to use the `table` command to include that new field.

### Important note

If you use `eval` command with field names that include non-alphanumeric characters, other than '\_', you must surround the field with **single quotation marks**. For example, if you are using 'server-1' field in your `eval` expression then you must do it like so

```
eval new=count+'server-1'
```

### Inline eval

If you use inline `eval` with commands such as `stats / chart` then you can evaluate new fields using the existing ones, you just need to use the `AS` to assign it to a new column. As opposite from doing `variable=<expression>`