'=' sign before interface components

Question

Hi, 
 I am wondering what does it mean by '=' sign before the interface components/what difference does it make by an '=' sign. 
 For example , in the documentation while giving example for BoxLayout , the code is written as 
 =a!boxLayout() and not a!boxLayout.

Ashvin Kapur · Answer

Hi Rohini, 
 
As far as I understand, there really isn't any reason for an "=" before the interface component. On an interface, you can optionally put an "=" sign before your code, but there is no advantage or disadvantage of doing so. I tend to omit the sign as the code is cleaner without it. 
 
I hope this helps! 
Ashvin

Mike Schmitt · Answer

More primitive appian expressions (like if you put an expression in a node input for example) require the "=" prior to expression code so that Appian knows to interpret it as an expression and not plain text. The "=" sign used to be required at the start of all expressions, expression rules, etc, but in recent releases has been largely mitigated. The only place I can still think of that it makes any difference is, as I mentioned, node inputs (to see what I mean, type in a literal value without the "=" and then open the expression editor for the field, and you should notice that the expression editor has interpreted it as a string, complete with quotes.) 
 www.screencast.com/.../fjQlBzG0th2G