Lookup Functions — VLOOKUP & INDEX/MATCH

Lookup functions let you pull matching information from another table instead of retyping it — essential for anything with a "list of items" and a "list of details," like a product catalog or staff directory.

• =VLOOKUP(lookup_value, table_range, column_number, FALSE) — finds a value in the first column of a range and returns a value from another column in the same row. Always use FALSE for an exact match.
• =INDEX(range, MATCH(lookup_value, lookup_range, 0)) — a more flexible alternative to VLOOKUP that can look left as well as right.
• Data Validation (Data → Data Validation): restrict a cell to a dropdown list of allowed values — prevents typos like "Nairobi" vs "nairobi" vs "Niarobi" in the same column.

Practical Skill: Build a simple inventory sheet with a product code list on one tab and a sales log on another tab that uses VLOOKUP to automatically pull the product name and price from the code entered.

=== SHEET 1: "Products" ===      A          B                C1     Code       Name             Price (SSP)2     P001       Exercise Book    1,2003     P002       Ballpoint Pen    3004     P003       USB Flash Drive  8,500 === SHEET 2: "Sales" ===      A          B                       C1     Code       Name                    Price2     P002       =VLOOKUP(A2,Products!A:C,2,FALSE)   =VLOOKUP(A2,Products!A:C,3,FALSE) Result: typing "P002" in A2 automatically fills in"Ballpoint Pen" and "300" — no retyping, no typos.