The first argument in the INDEX function is array. What is an array? An array is a range of cells. To demonstrate in greater detail that an array is an array of values you can convert an array or a cell reference to a static group of values by pressing F9.
INDEX((C11:E13,C18:E20),3,1,2) has two references to two different cell ranges. The area_num selects from which cell reference to return a value. In this example area_num is two and the second cell reference is used. The item in the third row and first column is returned.
Example 5 - Return a range of values
The formula in cell C19:E19 is an array formula. Select cell range C19:E19. Type =INDEX(C11:E13,3,0) in formula bar. Press and hold CTRL + SHIFT. Press Enter. Release all keys.
The example below returns all values from a column.
The example below returns all values from a two dimensional cell range.
This extensive function reference list provides detailed information including syntax, arguments, return values, and examples for many of the functions used in Excel formulas. Click on headers to sort table.
Article with the 'INDEX' Function
The following article has a formula that contains the INDEX function.