Choose the Quick Watch command from the Watch menu (or press SHIFT+F9) to display the Quick Watch dialog box. If the cursor is in the Source, Local, or Watch window, the variable at the current cursor position appears in the dialog box. If it isn't the item you want to display, type in the desired expression or variable; then press ENTER. The Quick Watch window immediately displays the specified item.
The Quick Watch display automatically expands structures and pointers to their first level. You can expand or contract an element just as you would in the Watch window: position the cursor on the appropriate line and press ENTER. If the array needs more lines than the Quick Watch window can display, drag the scroll box with the mouse, or press DOWN or PGDN to view the rest of the array.
Summary: You can add Quick Watch variables to the Watch window.
Choose the Add Watch button to add a Quick Watch item to the Watch window. Structures and pointers appear in the Watch window expanded as they were displayed in the Quick Watch dialog box.
Quick Watch is a convenient way to take a quick look at a variable or expression. Since only one Quick Watch variable can be viewed at a time, you would not use Quick Watch for most of the variables you want to view.