Some MEL commands can take an edit flag that allows you to make changes to the attributes of an object. The edit flag is used in conjunction with other flags specifying which attributes to change.
To edit objects with Maya commands
polyCube -edit -height 3;
This is equivalent to changing attribute values within the Attribute Editor in the Maya interface.
polySphere -edit -radius 1 test_Sphere;
Commands can operate on objects other than what is currently selected by specifying an object name as an argument. The name must be the last argument in the command.
delete;