File input loop with accumulator

Keywords: 
Loop
Do-Loop
Input
File
Situation: 

You have a file with data that you want to process. The amount of data in the file could change. You want to know something about the data set, like its total.

Actions: 

Initialize an accumulator variable. Loop while not EOF (end of file), reading data, and updating the accumulator each time through the loop. See the Explanation of this pattern for a flowchart and code.

Explanation: 

An accumulator is a variable that accumulates information about a data set. Here's a flowchart and code that shows how to use an accumulator with a file input loop.

Flowchart

  1. 'Initialize accumulator.
  2. itemCount = 0
  3. itemTotal = 0
  4. 'Open data file for input.
  5. Open ThisWorkbook.Path & "\filename.txt" For Input As #1
  6. 'Loop over the file.
  7. Do While Not EOF(1)
  8.     Input #1, item
  9.     itemCount = itemCount + 1
  10.     itemTotal = itemTotal + 1
  11. Loop
  12. 'Close the file.
  13. Close #1