Using Position correctly

Question

In the mma help docs for Position, the following is listed under \"Possible Issues\"

In[1]:= Position[Range[-1, 1, 0.05], 0.1]
Out[1]= {}

T

Answer 1

It is a numeric precision issue: 0.1 in the Range is not internally the same as 0.1 typed in. The normal way to resolve this is to compare with Equal rather than the implicit SameQ.

Position[Range[-1, 1, 0.05], x_ /; x == 0.1]