# Validating user input in excel vba

*23-Aug-2017 20:50*

This will enable your users to edit the source data without having to update the formula: Or, you may want to include an additional IF function(s) that fixes an upper, lower or both bounds of the amount range.

When the quantity is outside the range, the formula will display an "out of the range" message.

The Excel nested IF function evaluates the logical tests in the order they appear in the formula, and as soon as one of the conditions evaluates to TRUE, the subsequent conditions are not tested.

In other words, the formula stops after the first TRUE result. With B2 equal to 274, the nested IF formula below evaluates the first logical test (B2249, "Excellent", "Poor"))) The formula tests the first condition, and because 274 is greater than 150, the result of this logical test is also TRUE.

The logic is the same as in the above example, the only difference is that you multiply the specified quantity by the value returned by nested IFs (i.e. Assuming the user enters the quantity in cell B8, the formula is as follows: And the result will look something similar to this: As you understand, this example demonstrates only the general approach, and you can easily customize this nested If function depending on your particular task.

For example, instead of "hard-coding" the prices in the formula, you can reference the cells containing those values (cells B2 to B6).

Advanced Excel users that are familiar with array formulas, can use this formula that basically does the same thing as the nested IF function discussed above.

Though the array formula is far more difficult to comprehend, let along to write, it has one indisputable advantage - you specify the range of cells containing your conditions rather than referencing each condition individually.

In Excel 2016 - 2007, you can nest up to 64 IF functions.

When building a formula with multiple nested IF levels, you can make the formula's logic clearer by separating different IF functions with spaces or line breaks.

Excel doesn't care about extra spacing in a formula, so you may not worry about mangling it.

The underlined expression is the part currently under evaluation, and clicking the Evaluate button will show you all the steps in the evaluation process.

For example, the evaluation of the first logical test of the nested IF formula shown in the screenshot below will go as follows: B2249; TRUE; Excellent.

Further on in this tutorial, you will find a couple of Excel nested If examples along with the detailed explanation of their syntax and logic.