Remove last element from HTML using JavaScript 

const someElement.document.getElementById('someId')
someElement.removeChild(someElement.lastChild);

Remove all elements from a HTM element using JavaScript using loop 

document.getElementById('someId').prototype.empty = function() {
    var that = this;
    while (that.hasChildNodes()) {
        that.removeChild(that.lastChild);
    }
};

another way

const someElement = document.getElementById('someId');

someElement.innerHTML = '';