# Viewing runtime exceptions

If an expression you evaluate causes a runtime exception, the exception will be reported in the editor. For example:

Type and select the expression `Object x = null; x.toString()` in the editor and click Display in the toolbar.

The error message:

An exception occurred during evaluation: java.lang.NullPointerException

will be displayed in the editor.

Java editor

Displaying the result of evaluating an expression
Inspecting the result of evaluating an expression
Executing an expression