GOPATH environment variable (%GOPATH%, $GOPATH) will be created after you install Go on your computer.
What is it for?
This environment variable is used to find Go workspaces which contains binaries, packages, etc. For example, once
The default location is %USERPROFILE%/go on Windows or $HOME/go on Linux. Basically it locates in a subfolder named go under your user home folder.
Change it to other directory
To change it on Windows machine, go to Edit the system environment variable -> Environment Variables:
Click GOPATH variable and then edit the value:
Click OK button to save the changes.
To change it on UNIX-alike systems, edit .bashrc or .profile file.