MacLochlainns Weblog

It’s always interesting troubleshooting things that students run into when they work with Excel. For example, in Excel when is one not equal to one, or for that matter when is one less than one? If you use the CODE(cell_reference) function, you’d find both cells contain the same ASCII value of 49.

If you’re wondering why the one on the left is less than the one on the right, the one on the right is a text value and the one on the left is a number. If you use the TYPE(cell_reference) function, you’d find that a text field returns a 2 and a number (or date) cell returns a 1. All equality comparisons are identity comparisons in Microsoft Excel, which means they compare type and value. Inequality comparisons, compare type and return a value based on the type number and never compare value when the types differ. There are three other types: (1) A logical value is 4; (2) An error message is 16; and (3) An array is 64.

The answer is when one cell contains a number and the other cell contains a string (text value). That’s done here by putting an apostrophe before the number and right aligning the cell. You solve this by using the VALUE(cell_reference) function to ensure that you’re comparing values not unknown data types because there’s no implicit casting resolution in Microsoft Excel and all comparisons are identity operations.

I haven’t checked Open Office or Numbers, but I’ll do that and update this posting with findings.