What You'll Learn / Key Take-Aways

- The anatomy and syntax of the IF statement: `=IF(logical_test, value_if_true, value_if_false)`

- How to combine logical tests with `AND` and `OR` to evaluate multiple conditions

- When and how to use `NOT` and two forms of logical inversion

- Useful IS functions such as `ISBLANK`, `ISNUMBER`, `ISTEXT`, and `ISERROR` and when to use them

- Strategies for nesting IF statements and alternatives to avoid complexity

## Why logical operators matter

Logical operators let your spreadsheet make decisions for you. Instead of manually scanning rows or sorting data, you encode rules like If revenue is below target then flag it. Once you learn the core operators and patterns, you automate common tasks: classification, validation, error handling, and conditional calculations.

## Anatomy of the IF statement

The IF statement reads like a simple sentence.

- Syntax: `=IF(logical_test, value_if_true, value_if_false)`

- `logical_test` is an expression that evaluates to TRUE or FALSE. For example `A2>1000`.

- `value_if_true` is what Excel returns when the test is TRUE.

- `value_if_false` is what Excel returns when the test is FALSE.

Examples

- Basic numeric test: `=IF(A2>1000, "Above Target", "Below Target")`

- Boolean to number: `=IF(B2="Yes", 1, 0)`

Keep the logic simple and explicit. Use parentheses when combining comparisons to make your intent clear.

## Combining tests with AND and OR

When you need to check more than one condition, use `AND` and `OR`.

- `AND(condition1, condition2, ...)` returns TRUE only if all conditions are TRUE.

- `OR(condition1, condition2, ...)` returns TRUE if any condition is TRUE.

Examples inside IF

- Use AND to require multiple criteria: `=IF(AND(A2>1000, B2="East"), "Qualifies", "No")`

- Use OR to accept any matching criterion: `=IF(OR(A2>1000, C2>500), "Bonus", "No Bonus")`

Notes

- `AND` and `OR` accept multiple arguments.

- You can nest them: `=IF(AND(OR(A2="X", A2="Y"), B2>0), "OK", "No")`.

## The NOT function and logical inversion

`NOT` flips a logical value. `NOT(TRUE)` returns FALSE.

Common uses

- Negate a condition: `=IF(NOT(A2="Complete"), "Action Required", "Done")`

- Two forms of a not-like pattern: use `<>` for not-equal, and `NOT` for complex expressions. For example `A2<>"Yes"` is simpler than `NOT(A2="Yes")` for single comparisons.

## Nested IFs vs cleaner alternatives

Nested IFs let you test multiple outcomes in sequence. The general pattern is:

`=IF(test1, result1, IF(test2, result2, IF(test3, result3, result_default)))`

Example

`=IF(A2>1000, "High", IF(A2>500, "Medium", IF(A2>0, "Low", "None")))`

Pitfalls with nested IFs

- Readability drops quickly after 2 to 3 levels.

- Harder to maintain and debug.

Alternatives

- Use `IFS` if your Excel version supports it: `=IFS(A2>1000, "High", A2>500, "Medium", A2>0, "Low", TRUE, "None")`

- Use a lookup table with `VLOOKUP` or `INDEX`/`MATCH` for range-based classifications.

## Useful IS functions for validation and error handling

IS functions return TRUE or FALSE and are great for prechecks and guarding formulas.

- `ISBLANK(value)` returns TRUE if the cell is empty.

- `ISNUMBER(value)` checks for numeric values.

- `ISTEXT(value)` checks for text.

- `ISERROR(value)` returns TRUE for any error except `#N/A`.

- `ISNA(value)` specifically checks for `#N/A`.

Examples

- Prevent error propagation: `=IF(ISBLANK(A2), "", A2/B2)`

- Convert errors to friendly messages: `=IF(ISERROR(VLOOKUP(...)), "Not Found", VLOOKUP(...))`

Tip: Excel has `IFERROR(value, value_if_error)` as a compact alternative to `IF(ISERROR(...), ...)`.

## Practical patterns and examples

- Flagging by multiple criteria: `=IF(AND(ISNUMBER(A2), A2>0, B2<>""), "Valid", "Check")`

- Conditional sums with helper column: use IF to mark rows, then SUM the marks.

- Data cleaning: `=IF(ISNUMBER(--A2), --A2, "Invalid")` to coerce numeric-like text.

## Additional Tips, Pitfalls to Avoid & Pro Advice

- Keep tests readable. Break complex logic into helper columns when possible.

- Be explicit about blanks. An empty string `""` is not the same as a blank cell to some functions.

- Prefer `IFERROR` for simple error handling and `ISERROR` only when you need to handle different error types differently.

- When nesting, indent or use temporary columns to make debugging easier.

- Use `TRUE` and `FALSE` directly if appropriate: `=IF(B2=TRUE, ...)` can often be simplified to `=IF(B2, ...)`.

## FAQ

### How do I write an IF statement in Excel?

Use `=IF(logical_test, value_if_true, value_if_false)`. The logical test must return TRUE or FALSE. Example: `=IF(A2>1000, "Above", "Below")`.

### When should I use AND versus OR in an IF formula?

Use `AND` when all conditions must be true. Use `OR` when any condition can be true. For example `AND(A2>0, B2>0)` requires both positive values.

### How many nested IFs can I have and what is a better alternative?

You can nest many IFs, but readability suffers. Use `IFS` or a lookup table for multiple branches, or split logic into helper columns.

### What is the difference between ISBLANK and checking for an empty string?

`ISBLANK(A2)` returns TRUE only if the cell is truly empty. `A2=""` returns TRUE for an explicit empty string value, which can come from formulas.

### How do I avoid errors when dividing by zero in an IF formula?

Guard the divisor first: `=IF(B2=0, "No Div", A2/B2)` or use `=IFERROR(A2/B2, "Error")`.

## Summary of Key Points / Take-Home Messages

- Master the IF syntax first: `IF(logical_test, value_if_true, value_if_false)`.

- Use `AND` and `OR` to combine logical tests and `NOT` to invert them.

- Prefer `IFS`, lookup tables, or helper columns over deeply nested IFs.

- Use IS functions and `IFERROR` to validate inputs and handle errors gracefully.

- Keep formulas readable and test step by step when logic gets complex.

Congratulations on completing this core skill. Open the provided PDF and the Section Three Logical Operators Excel file to practice these patterns hands-on. High fives.