You use ____ classes in regular expressions to treat multiple characters as a single item.

In the computer industry, the term _________ refers to the size and dimensions of a device or components.

Fill in the blank(s) with the appropriate word(s).

Assume that nameJTextField is a JTextField. Find the error(s) in the following code:

``` 1 String name = nameJTextField.getText(); 2 3 if name.equals( "John Doe" ) 4 { 5 JOptionPane.showMessageDialog( "Welcome, John!", 6 JOptionPane.INFORMATION_MESSAGE ) 7 } ```