There are actions inside Nintex Workflow that expect a specific data type. If you're dealing with performing mathematical or datetime calculations or comparisons, the variables or values must be in the format that are required in those actions.
That is the whole purpose of the Convert Value action. It allows you to convert values stored in Text variables into other types of variables.
Imagine querying a database or a SharePoint list and getting the data back. In some cases, data is stored as text and you want to be able to perform calculations or comparisons. It is important that you have an action such as the Convert Value action to be able to handle this type of conversion.
Even though I've mentioned numbers and datetimes above, there are other variable types the Convert Value action supports. Specifically, converting Boolean, DateTime, Number, Integer and Guids. Below is a screenshot of a Convert Value action converting a typed in piece of text into a Boolean (Yes/No) variable.
Now usually, you won't be typing in data and instead converting one variable to another or an item property into a different variable type.
Ok... so lets get to the crux of this. In most cases Nintex Workflow is smart to realize that if you are dealing with a date, such as the Add Time to Date action, and you pass in a text variable, it will automatically convert it. But sometimes this doesn't work. It could be that the date format in your text string is not in your current sites regional settings. For example, if I was to put "20/01/2011 20:23" as a date time, my site would not recognize it as a valid date time. This is a format used in France. So if I wanted to do any sort of date/time calculation on this, I wouldn't be able to do it.
Now, I have the ability to convert that date/time from a text variable into a DateTime variable.
Notice that the Input regional settings were set to French (France). Now the action understands the format and converts it to a DateTime variable that I can do proper date calculations on.
Without the conversion, this would not be possible, because the Add Time to Date action would not recognize that text as a valid DateTime structure.
This is a great addition to the suite of Nintex Workflow actions for Office 365. If you have any questions or comments, please add them at the bottom of this post.
For more information about this action, see the Convert Value action in the Help.