Smalltalk User Guide : Inspecting and debugging code : Debugging code : Common errors to watch for : Messages not understood
Messages not understood
Debugger messages stating <class or object> does not understand <message> are probably the most common errors. The causes include:
• Misspelling the message selector
• Sending the message to a class that does not support it
• Sending the message to the wrong object
• Passing the wrong number of arguments
• Omitting a period or semicolon on the previous statement
• Omitting or mismatching parentheses
• Sending the message to an object that is nil
• Implementing a class method as an instance method, or vice versa
Last modified date: 01/29/2015