When JAVA_HOME is not set, then echo command will display the command instructions as it is:
C:\>echo %JAVA_HOME%
%JAVA_HOME%
To set the user environment variables, used setx command to do it.
setx JAVA_HOME "C:\jdk-8u172"
SUCCESS: Specified value was saved.
C:\>echo %JAVA_HOME%
%JAVA_HOME%
How to display the user environment variable details on the command line?
But when the JAVA_HOME is added with set command, then echo command displayed the path added in JAVA_HOME variable:
C:\>set JAVA_HOME="C:\jdk-8u172"
C:\>echo %JAVA_HOME%
"C:\jdk-8u172"
C:\Users\raju>
How echo command is restricted to display user environement variable details?