What is the INDEX Function
The INDEX function returns a value or reference from a table based on a row number and a column number that you specify. It is one of the two building blocks of the famous INDEX-MATCH combination and is more flexible than VLOOKUP.
Formula: =INDEX(array, row_num, [column_num])
Practical Example 1
Table A1:C5. Get the value at row 4, column 3.
Type: =INDEX(A1:C5, 4, 3)
Result: 40000
Practical Example 2
Get an entire column from a table.
Type: =INDEX(A1:C5, 0, 3)
Result: the entire third column
Practical Example 3
Combine INDEX with MATCH for a dynamic lookup.
Type: =INDEX(C:C, MATCH(Salma, A:A, 0))
Result: the value from column C where column A equals Salma
Practical Example 4
Return the Nth value from a single column.
Type: =INDEX(A:A, 5)
Result: the 5th value in column A
When to Use It
INDEX is used for dynamic lookups, for extracting values by position, for INDEX-MATCH combinations, and for any formula where you need to reference a specific cell by its row and column number.