Remove Duplicate Lines Calculator

How to Use This Calculator

1. Paste your text into the input area. Each line should be on a new line.
2. Click the "Calculate" button to process the text.
3. The calculator will remove duplicate lines while preserving the order of their first occurrence.
4. The result will be displayed in the output area.

Working Principle

This calculator uses a hash set (JavaScript Set object) to track unique lines. When processing each line:

• The line is trimmed to remove leading/trailing whitespace
• If the line has not been seen before, it's added to both the output array and the set of seen lines
• If the line has been seen before, it's ignored

Example

Input:

apple
                banana
                apple
                orange
                banana
                lemon

Output:

apple
                banana
                orange
                lemon

Applications

This calculator can be useful for:

• Cleaning log files to remove repeated entries
• Processing configuration files with duplicate lines
• Creating unique lists from input data
• Preparing data for analysis by removing duplicates