Zwcad Tips: How To Use The Select Command's Previous Option

By Author: Paul W. Walker
Total Articles: 7
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The Select command is one of the features we use the most during our daily CAD work. We have used it ever since we first touched a CAD software package, and so we are probably very familiar with it. Sometimes, however, we find that we don't fully understand it. Today I would like to share with you a small tip that might have been overlooked: the Select command's Previous option.

Typically, we select objects before starting the editing command. For example, in a word processor, we select a sentence first, and then press the DEL key to erase the sentence. ZWCAD also provides this "noun-verb" method of editing objects: select an object, and then enter the Erase command. However, we can reverse the procedure to select objects after starting the editing command ("verb-noun"), because certain of ZWCAD's commands require us to choose objects in a specific order, or might require objects that have a certain relationship to each other. For example, the Trim and Fillet commands require us to select some objects after we start the commands. But most editing commands ...
... allow us to work both ways, as with the Move, Copy, and Erase commands.

Both approaches are easily understood. But then there is the option named "Previous," which can be a little difficult to grasp. When, and how, do we use it? From the ZWCAD help document, we get this brief description: Selects the previous selection set. The previous selection set is deleted if you delete the objects in the selection set. The previous selection set created in model space is ignored if you switch to paper space.

Okay, let's say we are newbies, and so we are most likely to select objects before starting an editing command. It is natural that we use the mouse to pick the objects we want to edit. Sometimes, we succeed; in other cases, we find it is tough going, and so we use the Select command to help us select the objects. For example, we can use the Fence option to select an irregular line of objects. After selecting the objects, we start the editing command, such as Copy. Oh, oh: it prompts us to select one or more objects; where is our selection set? Do we need to select the objects again? Absolutely not, for ZWCAD saved the selection set for future use; we can access it by using the Previous option.

Command: copy
Select objects: previous
Select objects: (Press Enter to continue.)

Previous is like an assistant who remembers all of the objects selected by the last Select command. It saves the selection set for future use. Easy, right?

The figures above illustrate an example for users who are used to selecting objects before starting editing commands. On the left, the Fence option is selecting the objects; on the right, we see the selected objects highlighted. If you prefer to select objects after starting editing commands, then you can use the Previous option to refer to the selection set saved the last time the Select command was used. For example, you want to move some objects and then scale them. There is no need to select the objects twice, just use the Previous option when you use the Scale command.

If you have any other tips, please share them with us!