rust string contains

To check if a Rust string contains a specific substring, you can use the contains method provided by the str type. Here's an example:

fn main() {
    let my_string = "Hello, world!";
    let substring = "world";

    if my_string.contains(substring) {
        println!("The string contains the substring.");
    } else {
        println!("The string does not contain the substring.");
    }
}

In this example, the contains method is called on the my_string variable, passing the substring as an argument. The method returns a boolean value indicating whether the substring is present in the string. Based on the result, you can perform the desired actions.

Note that the contains method is case-sensitive. If you want to perform a case-insensitive search, you can convert both the string and the substring to lowercase or uppercase before calling the contains method.

I hope this helps! Let me know if you have any further questions.