I love keyboard shortcuts, but I must admit that while I use the heck out of them in InDesign and Photoshop, I’m not as fluent in Illustrator. Here are two handy shortcuts for selecting objects in your Adobe Illustrator document that I do use quite often.
To select all the objects on a layer in Illustrator, you can do one of two things. You can Option + Click on the layer in the layers panel, or click the tiny circle to the right of the layer name in the layers panel (as seen in the screenshot). Either way, only the objects on that layer will be selected.
Sure but it’s never a ‘keyboard shortcut’ if there’s a mouse involved.
A bit of clarification on this: You can click (no modifier keys needed) the spot with the little colored square to select all the objects on that layer. Even if the square is not showing (meaning nothing on that layer is currently selected) you can click that spot (where the square would be) to select all objects on the layer. This square is larger when all objects on that layer are selected.
You can also move the square (click & drag) to another layer to move the selected objects to that other layer.
Clicking on the circle will target the entire layer as a whole, instead of all of it’s contents. In this way, you can manipulate the transparency and many other appearance properties of the layer, not the individual objects or groups within that layer. (So if you’ve clicked the circle and targeted the entire layer, then changed the transparency settings, any new objects that are added to that layer will obtain the same transparency properties of that layer.)