Matlab function exist()

[Peter]

  Is there an equivalent for the Matlab function exist() which checks for the existence of variables, functions, etc?

[Avik Sengupta]

There is "isdefined" , which may be what you need. 

http://julia.readthedocs.org/en/latest/stdlib/base/?highlight=isdefined#Base.isdefined

eg: isdefined(Main, :x)