fn main() {
    // Creating String from string literal
    let s1: String = String::from("Hello, world!");
    
    // String slice - reference to part of a String
    let slice: &str = &s1[0..5];
    println!("Slice: {}", slice);
    
    // String methods
    let trimmed = "   spaces around   ".trim();
    println!("Trimmed: '{}'", trimmed);
    
    // Replacing text
    let replaced = s1.replace("world", "Rust");
    println!("Replaced: {}", replaced);
    
    // Checking prefixes and suffixes
    let phrase = String::from("Rust is awesome");
    println!("Starts with 'Rust': {}", phrase.starts_with("Rust"));
    println!("Ends with 'awesome': {}", phrase.ends_with("awesome"));
    
    // Converting to uppercase
    let upper = phrase.to_uppercase();
    println!("Uppercase: {}", upper);
}