I am using
SharePoint 2013 workflow, is there a way to
concat two string variables?
I don't see an activity for it!
SPD does not offer a concat function.
You can use SharePoint workflow variables and the String Builder dialog box in SharePoint Designer 2013 to be able to perform string concatenation.
This might help or check my steps below.
Step One: Create variables and put in a string.
Also CurrentItem can be used:
Step Two: Run the Workflow. Here my Output (Only the four variables in the StringBuilder):
If you think my answer is good, please give it a "vote up" or mark it as the answer if it fits perfectly for you.
Also uploaded a blogpost just now with a Step-by-Step "Storybook" of your question ;)