let x = new RegExp("d");

    document.write(x.test("My grilfriend's name is Ada.")+"</br>");

​

    let y = new RegExp("x");

    document.write(y.test("My grilfriend's name is Ada.")+"</br>");

​

    let z = new RegExp("y");

    document.write(z.exec("Would you marry me?")+"</br>");

​

    let a = new RegExp("n");

    document.write(a.exec("I just want to be your friend")+"</br>");