Configuring C++11/14 in Mac Terminal by default

I want to use c++11/14 features like range-based loops, but get a warning while doing g++ program.cpp. If done with compiler flag g++ -std=c++11 program.cpp the warning goes away. Is there a way to use c++11/14 by default on the g++ command (i.e without passing compiler flag every time).

Please explain to someone with limited knowledge of compilers and only need the c++11/14 features for competitive programming problems (even if it's a bad idea in general, maybe due to backward compatibility?)