Chapter 14: Introducing Arrays
In This Chapter
• Defining arrays and array formulas
• One-dimensional versus two-dimensional arrays
• How to work with array constants
• Techniques for working with array formulas
• Examples of multicell array formulas
• Examples of array formulas that occupy a single cell
One of Excel's most interesting (and most powerful) features is its ability to work with arrays in a formula. When you understand this concept, you can create elegant formulas that appear to perform magic. This chapter introduces the concept of arrays and is required reading for anyone who wants to become a master of Excel formulas. Chapter 15 continues with lots of useful examples.
Introducing Array Formulas
If you do any computer programming, you've probably been exposed to the concept of an array, which is a collection of items operated on collectively or individually. In Excel, an array can be one-dimensional or two-dimensional. These dimensions correspond to rows and columns. For example, a one-dimensional array can be stored in a range that consists of one row (a horizontal array) or one column (a vertical array). A two-dimensional array can be stored in a rectangular range of cells. Excel doesn't support three-dimensional arrays (although its VBA programming language does).
As you'll see, though, arrays need not be stored in cells. You can also work with arrays that exist only in Excel's memory. You can then use an array formula to manipulate this information and return ...