If you're using the MMA Console or local MMA web browser notebook installation, you can use some of the existing open source Wolfram Language(Wikipedia) packages.

One simple example is the BoolEval.m package, which you can load from the Github repository with this command:

<<"https://raw.githubusercontent.com/szhorvat/BoolEval/master/BoolEval/BoolEval.m"

Here are some examples from the MMAConsole:

>> <<"https://raw.githubusercontent.com/szhorvat/BoolEval/master/BoolEval/BoolEval.m"
In[1]:= <<"https://raw.githubusercontent.com/szhorvat/BoolEval/master/BoolEval/BoolEval.m"
>> array=Range[10]
In[2]:= array=Range[10]
Out[2]= {1,2,3,4,5,6,7,8,9,10}
>> BoolEval[array>3]
In[3]:= BoolEval[array>3]
Out[3]= {0,0,0,1,1,1,1,1,1,1}
>> BoolPick[array,array>3]
In[4]:= BoolPick[array,array>3]
Out[4]= {4,5,6,7,8,9,10}
>> BoolPick[array, Mod[array,3] == 1 && array<5]
In[5]:= BoolPick[array, Mod[array,3] == 1 && array<5]
Out[5]= {1,4}
>>