String Truncation

October 21, 2025 · View on GitHub

Humanizer provides intelligent string truncation with multiple strategies to handle different use cases.

Overview

Truncation is useful when you need to limit string length for display purposes while maintaining readability. Humanizer offers several truncation strategies and uses the … character (one character) instead of "..." (three characters) to maximize visible text.

Basic Usage

using Humanizer;

"Long text to truncate".Truncate(10) 
    // => "Long text…"

"Long text to truncate".Truncate(10, "---") 
    // => "Long te---"

Truncation Strategies

Fixed Length (Default)

Truncates to a specific total length including the truncation indicator:

"Long text to truncate".Truncate(10, Truncator.FixedLength) 
    // => "Long text…"

"Long text to truncate".Truncate(10, "---", Truncator.FixedLength) 
    // => "Long te---"

Fixed Number of Characters

Truncates to a specific number of alphanumeric characters:

"Long text to truncate".Truncate(6, Truncator.FixedNumberOfCharacters) 
    // => "Long t…"

"Long text to truncate".Truncate(6, "---", Truncator.FixedNumberOfCharacters) 
    // => "Lon---"

Fixed Number of Words

Truncates to a specific number of words:

"Long text to truncate".Truncate(2, Truncator.FixedNumberOfWords) 
    // => "Long text…"

"Long text to truncate".Truncate(2, "---", Truncator.FixedNumberOfWords) 
    // => "Long text---"

Dynamic Length - Preserve Words

Similar to fixed length but attempts to preserve whole words:

"Long text to truncate".Truncate(10, Truncator.DynamicLengthAndPreserveWords) 
    // => "Long text…"

"Long text to truncate".Truncate(10, "---", Truncator.DynamicLengthAndPreserveWords) 
    // => "Long---"

Dynamic Characters - Preserve Words

Similar to fixed number of characters but attempts to preserve whole words:

"Long text to truncate".Truncate(6, Truncator.DynamicNumberOfCharactersAndPreserveWords) 
    // => "Long…"

"Long text to truncate".Truncate(6, "---", Truncator.DynamicNumberOfCharactersAndPreserveWords) 
    // => "---"

Truncation Direction

By default, truncation happens from the right (end) of the string. You can truncate from the left (beginning) using TruncateFrom.Left:

"Long text to truncate".Truncate(10, Truncator.FixedLength, TruncateFrom.Left) 
    // => "… truncate"

"Long text to truncate".Truncate(10, "---", Truncator.FixedLength, TruncateFrom.Left) 
    // => "---runcate"

"Long text to truncate".Truncate(2, Truncator.FixedNumberOfWords, TruncateFrom.Left) 
    // => "…to truncate"

Custom Truncation Indicators

You can use any string as a truncation indicator:

"Long text to truncate".Truncate(15, " [more]") 
    // => "Long [more]"

"Long text to truncate".Truncate(15, "...") 
    // => "Long text..."

Custom Truncators

Implement the ITruncator interface to create custom truncation logic:

public interface ITruncator
{
    string Truncate(string value, int length, string truncationString, TruncateFrom truncateFrom = TruncateFrom.Right);
}

Example custom truncator:

public class SentenceTruncator : ITruncator
{
    public string Truncate(string value, int length, string truncationString, TruncateFrom truncateFrom)
    {
        // Custom logic to truncate at sentence boundaries
        // Implementation details...
    }
}

// Usage
"First sentence. Second sentence. Third sentence."
    .Truncate(30, new SentenceTruncator());

Real-World Examples

Truncate Article Previews

var article = "This is a very long article that needs to be truncated for the preview.";
var preview = article.Truncate(50, Truncator.FixedNumberOfWords);
// => "This is a very long article that needs to be…"

Truncate File Names

var fileName = "Very_Long_File_Name_That_Needs_Truncation.pdf";
var displayName = fileName.Truncate(20, "…", Truncator.DynamicLengthAndPreserveWords);
// => "Very_Long_File_Name…"

Truncate User Comments

var comment = "This is a user comment that might be too long to display in a notification.";
var notification = comment.Truncate(40);
// => "This is a user comment that might be…"

Best Practices

  1. Choose the right strategy:

    • Use FixedLength for consistent visual length
    • Use FixedNumberOfWords when word boundaries matter
    • Use dynamic strategies when readability is more important than exact length

  2. Consider the truncation indicator:

    • Use … (single character) for space efficiency
    • Use "..." if your audience expects it
    • Use " [more]" or similar for clarity

  3. Test with your actual content: Different text may truncate differently depending on word boundaries