How to Sort and Deduplicate Text

Problem

You have a list with duplicates and inconsistent ordering, and need a clean, sorted, unique list.

Prerequisites

• Understanding of sort orders
• Knowledge of duplicate detection

Steps

1. 1. Choose the sort order

   Decide between alphabetical (lexicographic), numerical, or natural sort. Alphabetical sorts character by character (so '10' comes before '2'). Numerical sorts by numeric value. Natural sort handles mixed text and numbers (so 'file2' comes before 'file10').

   Input

   sort: natural

   Output

   file2 before file10

2. 2. Remove duplicates

   After or before sorting, remove duplicate lines. Deduplication is case-sensitive by default ('Apple' and 'apple' are different). Choose case-insensitive deduplication if needed. Decide whether to keep the first or last occurrence of duplicates.

   Input

   lines with duplicates

   Output

   unique lines only

3. 3. Apply and output

   Run the sort and deduplication on the input list. The output is a sorted list with no duplicates. Verify the result by checking the line count and confirming the sort order is correct.

   Input

   3,1,2,1,3

   Output

   1,2,3

Expected result

A sorted list with all duplicates removed.

Common errors

Numbers sorted as strings

Use numerical sort for numbers. '10' should come after '2' numerically, but before it alphabetically.

Duplicates not removed due to whitespace

Trim whitespace before comparing. 'apple ' and 'apple' are different strings.

Troubleshooting

• If duplicates remain, check for trailing whitespace or different line endings.
• If sort order is wrong, verify the sort mode (alphabetical vs numerical vs natural).

Security limits

• Sorting and deduplication are pure text operations with no security implications.