What happens to an item already longer than the target width?

It's left completely unchanged. Padding only ever adds characters to reach the target width; it never truncates an item that's already at or beyond that width.

Can I use any fill character?

Any single character works, common choices are a space for text alignment or a symbol like "-" or "." for visual filler.

How is this different from List Left-Padder?

This tool adds fill characters after each item (right padding, via padEnd); List Left-Padder adds them before each item instead (left padding, via padStart).

Does this remove trailing whitespace or characters that are already there?

No, it only adds fill characters when an item is shorter than the target width; existing content is never removed.

List Right-Padder - Pad List Items to a Fixed Width

Overview

Introduction

Lists of values naturally come in varying lengths, which can make them awkward to display in a left-aligned, fixed-width layout.

List Right-Padder adds fill characters to the right of every item in a list so they all reach the same target width, without changing their content.

What Is List Right-Padder?

This is a per-item formatting tool: it walks every item in a list and, for each one shorter than your target width, adds fill characters on the right until it reaches that width.

It never removes characters and never affects an item longer than the target, only shorter items are extended.

How List Right-Padder Works

The list is split into items using your chosen separator, then each item is passed through `String.prototype.padEnd(width, fillChar)`.

Items already at or longer than the target width pass through completely untouched; only shorter items gain trailing fill characters.

When To Use List Right-Padder

Use this whenever you need a column of values to left-align within a fixed-width field, like formatting labels or names for a monospace report.

It's a natural pairing with List Left-Padder when different columns need different alignment.

Often used alongside List Left-Padder, List Item Trimmer and List Truncator.

Features

Advantages

Never changes an item's actual content, only adds fill characters to reach the target width.
Safe on mixed-length lists, items already wide enough are left untouched rather than causing an error.
Works with any single-character fill and any separator style.

Limitations

Only pads on the right; use List Left-Padder for the opposite direction.
Fill must be exactly one character; multi-character fills aren't supported.

Examples

Padding a mixed-length numeric list on the right

Input

1, 22, 333 (width: 4, fill: "0")

Output

1000, 2200, 3330

Each item gains exactly as many trailing zeros as it needs to reach 4 characters.

Space-padding for left-aligned column output

Input

a, bb (width: 3, fill: " ")

Output

a  , bb

Each item is left-aligned within a 3-character column using trailing spaces.

Best Practices & Notes

Best Practices

Use a space fill for left-aligned text columns, and a visible character like "-" if you want the padding to be obvious.
Pick a target width based on your longest expected item so nothing needs padding beyond what you intend.

Developer Notes

Each item is passed through JavaScript's built-in `String.prototype.padEnd(width, fillChar)`, which is a no-op when the string is already at or beyond the target length.

List Right-Padder Use Cases

Left-aligning a column of labels or names for a monospace report
Padding short codes with trailing characters to match a fixed-width field format
Preparing fixed-width fields for a downstream file format or API that expects trailing fill

Common Mistakes

Expecting padding to truncate items longer than the target width; it doesn't, by design, it only ever adds characters.
Trying to use a multi-character fill string, which the tool rejects since padEnd expects the pattern to repeat character by character.

Tips

If you want every item visually the same width regardless of its own length, pick a width at least as large as your longest expected item.
Combine with List Item Trimmer first if stray whitespace is throwing off your item widths.

List Right-Padder