How to set environment variables on MacOS?

There are two ways to set environment variables on MacOS (and I assumed is the same in linux):

1. Temporary
The easy and fast way to set an environment variable, and is perfect that tasks that required one of those.

export [VARIABLE_NAME]=[PATH]

Example:

export JAVA_HOME=/usr/libexec/java_home

Another example is when is required add a path to the PATH variable, without lost the current content:

export PATH=/THE/NEW/FOLDER/:$PATH

Unfortunately, is our terminal is closed, we lost the variables previously settled.

2. Permanently
If we need to keep the variables in a permanent way, we need not only use export command, but using on a file called .bash_profile. This file must be on the user folder, and normally it doesn't exist, so, we need to create it with our favorite editor, or using this command:

touch ~/.bash_profile

Inside this file we need to put all the path using export that we want:

export JAVA_HOME=/usr/libexec/java_home 

export PATH=/Users/username/Library/Android/sdk/platform-tools:$PATH

This file looks like:

That's all.