# Classpath Variables Preferences

## Configurable Variables

Classpath variables can be used in a Java Build Path to avoid a reference to the local file system. Using a variable entry, the classpath only contains a variable and the build path can be shared in a team. The value of such variables is configured on the Java > Build Path > Classpath Variables preference page.

Classpath variables
Command | Description
--- | ---
New... | Adds a new variable entry. In the resulting dialog, specify a name and path for the new variable. You can click the File or Folder buttons to browse for a path.
Edit... | Allows you to edit the selected variable entry. In the resulting dialog, edit the name and/or path for the variable. You can click the File or Folder buttons to browse for a path.
Remove | Removes the selected variable entry.

## Reserved Class Path Variables

Certain class path variables are set internally and can not be changed in the Classpath variables preferences:

- JRE_LIB: The archive with the runtime JAR file for the currently used JRE.
- JRE_SRC: The source archive for the currently used JRE.
- JRE_SRCROOT: The root path in the source archive for the currently used JRE.

These variables are deprecated and should not be used anymore. Instead use a JRE System Library.

### Related Concepts

Classpath variables

### Related References

Installed JREs