While
While[cond, body]
evaluates cond
, and if it returns True, evaluates body
. This happens repeatedly.
Attributes[While] := {HoldAll, Protected}
Simple examples
In[1]:= a = 1 Out[1]= 1
In[2]:= While[a != 5, a = a + 1] Out[2]= Null
In[3]:= a Out[3]= 5