AutoFill and Flash Fill in Excel - Cell-by-Cell Formula Trace

Sample Data

This data shows first and last names. Column C will be filled using AutoFill or Flash Fill.

Cell	Value
A1	First Name
A2	John
A3	Jane
A4	Mark
B1	Last Name
B2	Smith
B3	Doe
B4	Brown
C1	Full Name
C2	John Smith

Formula Trace

Flash Fill in C3:C4 to combine first and last names

Step 1: User types 'John Smith' in C2 as example

Step 2: Flash Fill detects pattern: combine A and B with space

Step 3: Apply pattern to C3: combine A3 and B3 with space

Step 4: Apply pattern to C4: combine A4 and B4 with space

Cell Reference Map

    A          B          C
1 |First Name|Last Name |Full Name
2 |John      |Smith     |John Smith
3 |Jane      |Doe       |<-- Flash Fill uses A3 and B3
4 |Mark      |Brown     |<-- Flash Fill uses A4 and B4

Cells A2:A4 and B2:B4 provide first and last names. Flash Fill uses these to fill column C.

Result

    A          B          C
1 |First Name|Last Name |Full Name
2 |John      |Smith     |John Smith
3 |Jane      |Doe       |Jane Doe
4 |Mark      |Brown     |Mark Brown

Column C shows full names created by combining first and last names using Flash Fill.

Sheet Trace Quiz - 3 Questions

What does Flash Fill use to fill cells in column C?

A A formula referencing columns A and B

B The pattern from the example typed in C2

C Random values from column B

D Values only from column A

Key Result

Flash Fill detects user example pattern and applies it to fill cells automatically.