javscript remove class

function myFunction() {
  var element = document.getElementById("myDIV");

    element.classList.remove("mystyle");
} 

document.getElementsByClassName("legend").style.display="none";

const removeClass = (element, name) => {
    const pattern = new RegExp('(?:^|\\s)'+ name + '(?:\\s|$)', 'g');
    element.className = element.className.replace(pattern, "");
};