RUST: String methods

//! Comprehensive String method examples with detailed explanations

pub fn demonstrate_string_methods() {
    /* 1. CREATION AND CONVERSION METHODS */
    // From string literal
    let from_literal = String::from("Hello");
    // From &str slice
    let from_str = "World".to_string();
    // From single char
    let from_char = '!'.to_string();
    // From UTF-8 bytes
    let from_bytes = String::from_utf8(vec![72, 101, 108, 108, 111]).unwrap();

    /* 2. CAPACITY MANAGEMENT */
    let mut s = String::with_capacity(10);
    println!("Initial capacity: {}", s.capacity());
    s.push_str("Rust");
    s.reserve(20);
    s.shrink_to_fit();

    /* 3. MODIFICATION METHODS */
    s.push('!');
    s.push_str(" is awesome");
    s.insert(5, ' ');
    s.insert_str(0, "Hey! ");

    /* 4. REMOVAL METHODS */
    let popped = s.pop();
    s.remove(0);
    s.truncate(10);
    s.clear();

    /* 5. SLICING AND ACCESS */
    s = String::from("Rust Programming");
    let first_word = s.get(0..4).unwrap();
    let first_char = s.chars().next().unwrap();
    let bytes = s.as_bytes();

    /* 6. SEARCH METHODS */
    let contains_pro = s.contains("Pro");
    let find_gram = s.find("gram").unwrap();
    let matches: Vec<&str> = s.matches("r").collect();

    /* 7. SPLITTING METHODS */
    let words: Vec<&str> = s.split_whitespace().collect();
    let lines: Vec<&str> = "line1\nline2".lines().collect();
    let split: Vec<&str> = s.split(' ').collect();

    /* 8. TRANSFORMATION METHODS */
    let upper = s.to_uppercase();
    let lower = s.to_lowercase();
    let replaced = s.replace("Programming", "Language");
    let trimmed = "  Rust  ".trim().to_string();

    /* 9. UTF-8 METHODS */
    let char_count = s.chars().count();
    let is_ascii = s.is_ascii();

    /* 10. CONVERSION METHODS */
    let byte_vec = s.into_bytes();
    let s = String::from_utf8(byte_vec).unwrap();
    let str_slice: &str = s.as_str();
}

// Remember to add to src/menu_items/mod.rs:
// pub mod string_methods_demo;