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Tech Tip: Combo box vs. Pop-up/Drop-down list
PRODUCT: 4D | VERSION: 6.5 | PLATFORM: Mac & Win
Published On: September 21, 2001

Both Combo box and Pop-up/Drop-down list controls are associated with arrays. The way these controls behave is similar; the only key difference is what happens when an element is selected. With a Combo box, the value of the selected element is assigned to element 0 (zero) in the array (e.g. ComboBoxArray{0} or ComboBoxArray{ComboBoxArray}).


With the Pop-up/Drop-down list, element 0 in the array is always empty. The value of the selected element is never copied to the element 0. Instead, the selected element index is assigned to the array variable (PopupArray). Therefore, the safest way to get the value of the selected element is to call PopupArray{PopupArray}.