clsString.h - Comprehensive String Utility Class for C++

🧩 Overview

clsString is a modern, lightweight, and reusable C++ header-only class that simplifies string handling and manipulation.

It provides powerful tools for case conversion, trimming, splitting, joining, counting, and replacing operations — all without requiring external dependencies.

This library is designed to make string processing cleaner, faster, and easier in your C++ projects.

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🚀 Key Features

✏️ Basic Operations

• Length() — returns string length.
• CountWords() — counts words separated by spaces.
• Split() — splits a string into a vector using a delimiter.
• JoinString() — joins an array or vector of strings into one string.
• TrimLeft(), TrimRight(), Trim() — removes leading/trailing spaces.

🔠 Case Manipulation

• UpperAllString() / LowerAllString()
• UpperFirstLetterOfEachWord() / LowerFirstLetterOfEachWord()
• InvertAllLettersCase() — inverts character case for each letter.
• InvertLetterCase(char) — toggles a single character’s case.

🔍 Counting Tools

• CountLetters() — counts capital/small letters or all characters.
• CountCapitalLetters(), CountSmallLetters()
• CountSpecificLetter() — counts how many times a given character appears (case-sensitive or not).
• CountVowels() — returns the number of vowels (A, E, I, O, U).

🧹 Cleaning & Editing

• RemovePunctuations() — removes punctuation marks from a string.
• ReplaceWord() — replaces occurrences of a word (with optional case-sensitivity).
• ReverseWordsInString() — reverses the order of words in a sentence.

🧠 Object-Oriented Integration

• Works both statically and as an object:

  clsString myText("hello world");
  myText.UpperAllString(); // modifies the object directly

• Uses a property system:

  myText.Value = "New Text";
  cout << myText.Value;

⚙️ Enums

• enWhatToCount enum allows custom count behavior:
  • SmallLetters
  • CapitalLetters
  • All

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💡 Example Usage

#include <iostream>
#include "clsString.h"
using namespace std;

int main()
{
    clsString text("hello world from cpp");

    cout << "Original: " << text.GetValue() << endl;
    cout << "Length: " << text.Length() << endl;
    cout << "Words: " << text.CountWords() << endl;

    text.UpperFirstLetterOfEachWord();
    cout << "Title Case: " << text.GetValue() << endl;

    text.InvertAllLettersCase();
    cout << "Inverted Case: " << text.GetValue() << endl;

    cout << "Vowels: " << text.CountVowels() << endl;

    string reversed = clsString::ReverseWordsInString("C++ is fun to learn");
    cout << "Reversed Words: " << reversed << endl;

    string cleaned = clsString::RemovePunctuations("Hi! This, is a test...");
    cout << "Cleaned: " << cleaned << endl;

    return 0;
}

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🧪 Testing Guide

You can validate each function individually or run unit tests using assert():

#include "clsString.h"
#include <cassert>
#include <iostream>
using namespace std;

int main()
{
    clsString s("hello world");
    assert(s.Length() == 11);
    assert(s.CountWords() == 2);
    assert(clsString::CountVowels("education") == 5);
    assert(clsString::Trim("   text  ") == "text");
    assert(clsString::ReplaceWord("I love C++", "love", "use") == "I use C++");
    assert(clsString::ReverseWordsInString("C++ is fun") == "fun is C++");

    cout << "All tests passed successfully!" << endl;
}

Compile and run:

g++ -std=c++17 test_clsString.cpp -o test && ./test

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🧾 Example Output

Original: hello world from cpp
Length: 19
Words: 4
Title Case: Hello World From Cpp
Inverted Case: hELLO wORLD fROM cPP
Vowels: 5
Reversed Words: learn to fun is C++
Cleaned: Hi This is a test
All tests passed successfully!

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⚡ Performance & Compatibility

• Header-only: Just #include "clsString.h"
• No dynamic allocations besides STL containers.
• Compatible with C++11 and newer.
• Works on Windows, Linux, and macOS.

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🧱 Class Structure

clsString.h
└── clsString
    ├── Constructors
    ├── Static string utilities
    ├── Object-based instance functions
    ├── enWhatToCount enum
    └── String manipulation toolkit

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🧰 Future Enhancements

• Add substring search and replace by index.
• Add string comparison ignoring case.
• Add conversion tools (to upper snake case, kebab case, etc.).
• Add UTF-8 and wide string support.

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📜 License

Open-source and free for educational or commercial use.