Zeba Academy String Utils

A lightweight, dependency-free collection of string manipulation utilities for Dart and Flutter applications.

zeba_academy_string_utils provides practical helpers for whitespace cleanup, truncation, repetition, character validation, word counting, safe substring operations, normalization, and more.

✨ Features

🧹 Trim leading and trailing whitespace
🧽 Clean and collapse consecutive whitespace
🚫 Remove all whitespace
✂️ Safely truncate strings
🔁 Repeat strings
🔤 Check alphabetic strings
🔢 Check numeric strings
🔤🔢 Check alphanumeric strings
🔠 Detect uppercase characters
🔡 Detect lowercase characters
🔢 Detect digits
␠ Detect whitespace
📝 Count words
🛡️ Safely extract substrings
🧹 Normalize strings
🔡 Convert strings to lowercase
🔠 Convert strings to uppercase
⬜ Detect blank strings
🧩 Convenient String extensions
📦 Zero external runtime dependencies
🎯 Simple and predictable API

📦 Installation

Add the package to your pubspec.yaml:

dependencies:
  zeba_academy_string_utils: ^1.0.0

Then run:

flutter pub get

🚀 Quick Start

Import the package:

import 'package:zeba_academy_string_utils/zeba_academy_string_utils.dart';

You can use the static utility API:

final cleaned = ZebaStringUtils.cleanWhitespace(
  '  Hello    Flutter   World  ',
);

print(cleaned);
// Hello Flutter World

Or use the convenient string extensions:

final result = '  HELLO   WORLD  '.zNormalize();

print(result);
// hello world

🧰 API Reference

Whitespace Utilities

`trim`

Removes leading and trailing whitespace.

final result = ZebaStringUtils.trim('  Hello World  ');

print(result);
// Hello World

Extension:

final result = '  Hello World  '.zTrim();

`cleanWhitespace`

Trims the string and collapses consecutive whitespace characters into a single space.

final result = ZebaStringUtils.cleanWhitespace(
  '  Hello    beautiful   world  ',
);

print(result);
// Hello beautiful world

Extension:

final result = '  Hello    World  '.zCleanWhitespace();

`removeWhitespace`

Removes all whitespace characters.

final result = ZebaStringUtils.removeWhitespace(
  'Hello World',
);

print(result);
// HelloWorld

Extension:

final result = 'Hello World'.zRemoveWhitespace();

✂️ Truncation

`truncate`

Truncates a string to the specified maximum length.

final result = ZebaStringUtils.truncate(
  'Hello Flutter Developer',
  12,
);

print(result);
// Hello Fl...

The default ellipsis is:

...

You can provide a custom ellipsis:

final result = ZebaStringUtils.truncate(
  'Hello Flutter Developer',
  12,
  ellipsis: '…',
);

print(result);
// Hello Flutt…

Extension:

final result = 'Hello Flutter Developer'.zTruncate(12);

Edge Cases

If the string is already within the requested length, it is returned unchanged.

ZebaStringUtils.truncate('Hello', 10);
// Hello

A negative maxLength throws an ArgumentError.

🔁 Repetition

`repeat`

Repeats a string the requested number of times.

final result = ZebaStringUtils.repeat(
  'ab',
  3,
);

print(result);
// ababab

Extension:

final result = 'ab'.zRepeat(3);

A count of zero returns an empty string:

ZebaStringUtils.repeat('Hello', 0);
// ''

A negative count throws an ArgumentError.

🔤 Character Checks

`isAlphabetic`

Checks whether a string contains only alphabetic ASCII characters.

ZebaStringUtils.isAlphabetic('Hello');
// true

ZebaStringUtils.isAlphabetic('Hello123');
// false

Extension:

'Hello'.zIsAlphabetic;

`isNumeric`

Checks whether a string contains only numeric ASCII digits.

ZebaStringUtils.isNumeric('12345');
// true

ZebaStringUtils.isNumeric('123abc');
// false

Extension:

'12345'.zIsNumeric;

`isAlphanumeric`

Checks whether a string contains only alphabetic and numeric ASCII characters.

ZebaStringUtils.isAlphanumeric('Flutter123');
// true

ZebaStringUtils.isAlphanumeric('Flutter 123');
// false

Extension:

'Flutter123'.zIsAlphanumeric;

`hasUppercase`

Checks whether the string contains at least one uppercase character.

ZebaStringUtils.hasUppercase('helloWorld');
// true

ZebaStringUtils.hasUppercase('hello');
// false

Extension:

'helloWorld'.zHasUppercase;

`hasLowercase`

Checks whether the string contains at least one lowercase character.

ZebaStringUtils.hasLowercase('HELLOw');
// true

ZebaStringUtils.hasLowercase('HELLO');
// false

Extension:

'HELLOw'.zHasLowercase;

`hasDigit`

Checks whether the string contains at least one digit.

ZebaStringUtils.hasDigit('Flutter123');
// true

ZebaStringUtils.hasDigit('Flutter');
// false

Extension:

'Flutter123'.zHasDigit;

`hasWhitespace`

Checks whether the string contains at least one whitespace character.

ZebaStringUtils.hasWhitespace('Hello World');
// true

ZebaStringUtils.hasWhitespace('Hello');
// false

Extension:

'Hello World'.zHasWhitespace;

📝 Word Counting

`wordCount`

Counts words separated by whitespace.

final count = ZebaStringUtils.wordCount(
  'Hello beautiful Flutter world',
);

print(count);
// 4

Multiple whitespace characters are handled automatically:

ZebaStringUtils.wordCount(
  'Hello    beautiful\nFlutter\tworld',
);
// 4

Empty or whitespace-only strings return 0.

Extension:

final count = 'Hello Flutter Developer'.zWordCount;

🛡️ Safe Substring

`safeSubstring`

Extracts a substring without throwing when the requested indexes exceed the string's boundaries.

final result = ZebaStringUtils.safeSubstring(
  'Hello World',
  0,
  100,
);

print(result);
// Hello World

A negative start index is safely clamped:

ZebaStringUtils.safeSubstring(
  'Hello',
  -10,
  3,
);
// Hel

An index beyond the string length returns an empty string:

ZebaStringUtils.safeSubstring(
  'Hello',
  100,
);
// ''

You can also omit the end index:

ZebaStringUtils.safeSubstring(
  'Hello World',
  6,
);
// World

Extension:

final result = 'Hello World'.zSafeSubstring(0, 100);

🧹 Normalization

`normalize`

Normalizes a string by:

Trimming leading whitespace.
Trimming trailing whitespace.
Collapsing consecutive whitespace.
Converting the result to lowercase.

final result = ZebaStringUtils.normalize(
  '  HELLO    Flutter   WORLD  ',
);

print(result);
// hello flutter world

Extension:

final result = '  HELLO   WORLD  '.zNormalize();

This is useful when comparing user input:

final first = ZebaStringUtils.normalize('  Hello World ');
final second = ZebaStringUtils.normalize('HELLO   WORLD');

print(first == second);
// true

🔡 Case Conversion

`lowercase`

final result = ZebaStringUtils.lowercase('HELLO');

print(result);
// hello

Extension:

'HELLO'.zLowercase();

`uppercase`

final result = ZebaStringUtils.uppercase('hello');

print(result);
// HELLO

Extension:

'hello'.zUppercase();

⬜ Blank String Checks

`isBlank`

Checks whether a string is empty after trimming whitespace.

ZebaStringUtils.isBlank('');
// true

ZebaStringUtils.isBlank('   ');
// true

ZebaStringUtils.isBlank('Hello');
// false

Extension:

'   '.zIsBlank;

`isNotBlank`

The opposite of isBlank.

ZebaStringUtils.isNotBlank('Hello');
// true

ZebaStringUtils.isNotBlank('   ');
// false

Extension:

'Hello'.zIsNotBlank;

🧩 Extension API

The package provides convenient extensions directly on String.

import 'package:zeba_academy_string_utils/zeba_academy_string_utils.dart';

void main() {
  final value = '  Hello   Flutter 123  ';

  print(value.zTrim());
  print(value.zCleanWhitespace());
  print(value.zRemoveWhitespace());
  print(value.zTruncate(10));
  print(value.zRepeat(2));

  print(value.zIsAlphabetic);
  print(value.zIsNumeric);
  print(value.zIsAlphanumeric);

  print(value.zHasUppercase);
  print(value.zHasLowercase);
  print(value.zHasDigit);
  print(value.zHasWhitespace);

  print(value.zWordCount);
  print(value.zSafeSubstring(0, 100));
  print(value.zNormalize());

  print(value.zLowercase());
  print(value.zUppercase());

  print(value.zIsBlank);
  print(value.zIsNotBlank);
}

🎯 Static API vs Extensions

Both styles are supported.

Static API

Useful when you want an explicit utility class:

ZebaStringUtils.normalize(value);

Extension API

Useful when working directly with strings:

value.zNormalize();

Choose whichever style fits your project.

📋 Complete API

Method	Description
`trim()`	Removes surrounding whitespace
`cleanWhitespace()`	Trims and collapses whitespace
`removeWhitespace()`	Removes all whitespace
`truncate()`	Safely truncates a string
`repeat()`	Repeats a string
`isAlphabetic()`	Checks alphabetic characters
`isNumeric()`	Checks numeric characters
`isAlphanumeric()`	Checks alphanumeric characters
`hasUppercase()`	Checks for uppercase characters
`hasLowercase()`	Checks for lowercase characters
`hasDigit()`	Checks for digits
`hasWhitespace()`	Checks for whitespace
`wordCount()`	Counts words
`safeSubstring()`	Safely extracts a substring
`normalize()`	Normalizes whitespace and case
`lowercase()`	Converts to lowercase
`uppercase()`	Converts to uppercase
`isBlank()`	Checks for blank strings
`isNotBlank()`	Checks for non-blank strings

🧪 Testing

The package includes comprehensive tests covering:

Whitespace handling
Truncation
Custom ellipsis
String repetition
Character validation
Uppercase/lowercase detection
Digit detection
Word counting
Safe substring boundaries
Normalization
Case conversion
Blank string detection
Extension methods
Edge cases
Invalid arguments

Run tests with:

flutter test

Run static analysis with:

flutter analyze

Format the project with:

dart format lib test

🔒 Dependencies

zeba_academy_string_utils has zero external runtime dependencies.

It uses only the Dart core libraries and is designed to remain lightweight and easy to integrate into existing Dart and Flutter projects.

🎯 Design Goals

This package follows a few simple principles:

Simple — APIs should be easy to understand.
Predictable — Edge cases should have consistent behavior.
Lightweight — No unnecessary dependencies.
Reusable — Utilities should work across Dart and Flutter applications.
Type-safe — APIs should leverage Dart's type system.
Tested — Common and edge-case behavior should be covered by tests.
Production-ready — Suitable for real-world applications.

🤝 Contributing

Contributions are welcome!

If you discover a bug, have an improvement, or want to suggest a feature:

Fork the repository.
Create a feature branch.
Make your changes.
Add or update tests.
Run dart format.
Run flutter analyze.
Run flutter test.
Submit a pull request.

Please keep contributions focused and aligned with the package's goal of providing small, reusable string utilities.

📄 License

This project is licensed under the GNU General Public License v3.0 (GPL-3.0).

See the LICENSE file for the complete license text.

👨‍💻 About Me

✨ I'm Sufyan bin Uzayr, an open-source developer passionate about building and sharing meaningful projects.

You can learn more about me and my work at sufyanism.com or connect with me on LinkedIn.

🎓 Your All-in-One Learning Hub!

🚀 Explore courses and resources in coding, tech, and development at zeba.academy and code.zeba.academy.

Empower yourself with practical skills through curated tutorials, real-world projects, and hands-on experience. Level up your tech game today! 💻✨

Zeba Academy is a learning platform dedicated to coding, technology, and development.

➡ Visit our main site: zeba.academy

➡ Explore hands-on courses and resources at code.zeba.academy

➡ Check out our YouTube for more tutorials: Zeba Academy

➡ Follow us on Instagram: Zeba Academy

Thank you for visiting! ❤️

⭐ Support

If you find this package useful, consider giving the project a ⭐ on GitHub and sharing it with other Dart and Flutter developers.

Built with ❤️ for the Dart & Flutter community by Zeba Academy.

Zeba Academy String Utils

✨ Features

📦 Installation

🚀 Quick Start

🧰 API Reference

Whitespace Utilities

trim

cleanWhitespace

removeWhitespace

✂️ Truncation

truncate

Edge Cases

🔁 Repetition

repeat

🔤 Character Checks

isAlphabetic

isNumeric

isAlphanumeric

hasUppercase

hasLowercase

hasDigit

hasWhitespace

📝 Word Counting

wordCount

🛡️ Safe Substring

safeSubstring

🧹 Normalization

normalize

🔡 Case Conversion

lowercase

uppercase

⬜ Blank String Checks

isBlank

isNotBlank

🧩 Extension API

🎯 Static API vs Extensions

Static API

Extension API

📋 Complete API

🧪 Testing

🔒 Dependencies

🎯 Design Goals

🤝 Contributing

📄 License

👨‍💻 About Me

🎓 Your All-in-One Learning Hub!

⭐ Support

Libraries

zeba_academy_string_utils package

`trim`

`cleanWhitespace`

`removeWhitespace`

`truncate`

`repeat`

`isAlphabetic`

`isNumeric`

`isAlphanumeric`

`hasUppercase`

`hasLowercase`

`hasDigit`

`hasWhitespace`

`wordCount`

`safeSubstring`

`normalize`

`lowercase`

`uppercase`

`isBlank`

`isNotBlank`