js body最后追加内容

document.body.innerHTML += '<p>这是追加的内容。</p>';

var newElement = document.createElement('p');
newElement.textContent = '这是追加的内容。';
document.body.appendChild(newElement);

var fragment = document.createDocumentFragment();
for (var i = 0; i < 10; i++) {
    var newElement = document.createElement('p');
    newElement.textContent = '这是追加的内容。';
    fragment.appendChild(newElement);
}
document.body.appendChild(fragment);

function escapeHtml(unsafe) {
    return unsafe
         .replace(/&/g, "&")
         .replace(/</g, "&lt;")
         .replace(/>/g, "&gt;")
         .replace(/"/g, "&quot;")
         .replace(/'/g, "&#039;");
}

var userInput = '<script>alert("XSS")</script>';
var safeInput = escapeHtml(userInput);
document.body.innerHTML += '<p>' + safeInput + '</p>';