String replace limited times

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examples/strings/replacen/src/main.rs

fn main() {
    let text = String::from("Black cat, brown cat, many cats and a dog");
    println!("{text}");

    let new = text.replacen("cat", "mouse", 2);
    println!("{new}");
    println!("{text}");
}

Black cat, brown cat, many cats and a dog
Black mouse, brown mouse, many cats and a dog
Black cat, brown cat, many cats and a dog