Overview
Introduction
Sometimes you need to substitute one specific digit character for another throughout a whole list of hex values, correcting a systematic typo, anonymizing a repeated digit, or experimenting with how a value changes under a substitution.
This tool performs exactly that: a single-character find/replace applied consistently across every value in a list of hex values.
What Is Hex Digit Replacer?
The Hex Digit Replacer takes two single-character fields, the digit to find and the digit to replace it with, and applies that substitution to every matching occurrence across every value in your list.
Matching on the "find" character is case-insensitive, so it doesn't matter whether your input or the find field use upper or lower case; the output is always normalized to uppercase.
How Hex Digit Replacer Works
Both the find and replace fields are validated as single hex digit characters (0-9 or A-F); anything else is rejected with a clear error before any substitution happens.
Each value in the parsed input list then has every occurrence of the find digit swapped for the replace digit, using a straightforward split-and-join substitution, and the results are joined back into a list, one value per line.
When To Use Hex Digit Replacer
Use this when a specific digit needs to change consistently across many values at once, for example correcting a digit that was systematically mistyped or misread across a whole dataset.
It's also handy for quick experimentation, seeing how a set of values shifts when one particular digit is swapped for another, without editing each value by hand.
Often used alongside Hex Digit Remover, Hex Digit Sorter and Hex Digit Incrementer.
Features
Advantages
- Applies the exact same substitution to every value in the list in one pass, rather than requiring manual per-value edits.
- Case-insensitive matching means you don't need to worry about the input's letter casing when specifying the find digit.
- Validates both fields as single hex digits up front, so a mistaken multi-character entry is caught immediately rather than silently doing nothing.
Limitations
- Only a single find/replace pair per run; chaining multiple digit substitutions requires running the tool again on its own output.
- Replacing a digit changes affected values' numeric meaning; this is not a value-preserving operation.
Examples
Best Practices & Notes
Best Practices
- Double-check both fields hold exactly one character each; anything else is rejected with an error rather than silently truncated.
- If you need several substitutions done in sequence, run the tool once per digit, feeding each result into the next round.
Developer Notes
Substitution is implemented as `value.split(find).join(replace)` on each already-uppercased value, which correctly replaces every occurrence in one pass without the regex-escaping concerns a regex-based `replaceAll` would introduce for special characters (not an issue here since inputs are restricted to single hex digit characters, but worth noting as the reason for this approach).
Hex Digit Replacer Use Cases
- Correcting a digit that was consistently mistyped or OCR-misread across a batch of hex values
- Quick "what if this digit were different" experimentation across a list of values
- Lightweight digit-level anonymization or obfuscation of a repeated character in sample data
Common Mistakes
- Entering more than one character in the find or replace field; both must be exactly one hex digit character.
- Expecting the substitution to preserve the value's numeric meaning; replacing a digit generally changes what number the value represents.
Tips
- Use Hex Number Analyzer afterward on a specific value to see exactly how the substitution changed its decimal equivalent.
- For removing a digit entirely rather than swapping it for another, use Hex Digit Remover instead.