Finding first element of a Mathematica list greater than a threshold

Question

I was wondering how I could obtain the first element of a (already ordered) list that is greater than a given threshold.

I don't know really well the list manipulation function in Mathematica, maybe someone can give me a trick to do that efficiently.

Answer 1

Select does what you need, and will be consistent, respecting the pre-existing order of the list:

Select[list, # > threshold &, 1]

For example:

In[1]:= Select[{3, 5, 4, 1}, # > 3 &, 1]

Out[1]= {5}

You can provide whatever threshold or criterion function you need in the second argument.

The third argument specifies you only one (i.e., the first) element that matches.

Hope that helps!