我正在建立一个网页。在我的菜单页面上，我试图制作一个功能，当我单击素食选项时，主要选项消失，而素食选项出现。但是，这需要使用 javascript，而我对 javascript 很陌生。我创建了一个名为 showveg() 的函数（如下），但为我的按钮创建了一个 onclick 函数，但没有任何反应。这是我的代码。
// function displayhidden(class){
// document.getElementByClass("menumain").style.display = "hidden";
// }
function showveg() {
document.getElementByClass("menumain").style.visibility = "hidden";
document.getElementByClass("price").style.visibility = "hidden";
document.getElementByClass("dishtitle").style.visibility = "hidden";
document.getElementByClass("dishinfo").style.visibility = "hidden";
document.getElementByClass("key").style.visibility = "hidden";
document.getElementByClass("doro").style.visibility = "hidden";
document.getElementByClass("yebeg").style.visibility = "hidden";
document.getElementByClass("kitfo").style.visibility = "hidden";
document.getElementByClass("beeftibs").style.visibility = "hidden";
document.getElementByClass("lambtibs").style.visibility = "hidden";
document.getElementByClass("menuveg").style.visibility = "visible";
document.getElementByClass("price2").style.visibility = "visible";
document.getElementByClass("dishtitle2").style.visibility = "visible";
document.getElementByClass("dishinfo2").style.visibility = "visible";
document.getElementByClass("key2").style.visibility = "visible";
document.getElementByClass("doro2").style.visibility = "visible";
document.getElementByClass("yebeg2").style.visibility = "visible";
document.getElementByClass("kitfo2").style.visibility = "visible";
document.getElementByClass("beeftibs2").style.visibility = "visible";
document.getElementByClass("lambtibs2").style.visibility = "visible"; …