JavaScript函数赢得'；不管我怎么努力都不行

我是JavaScript的新手，不好意思说我搞不懂这个。我试图创建一个网站，解析名字和姓氏输出电子邮件地址。我将onclick（）函数移到onload（）之外，这只会产生更多问题。任何帮助都将不胜感激。我为我的无知道歉

HTML:

---

您可以在JavaScript中尝试以下代码：

window.onload = function() {
  //alert("Just finished loading the webpage in the window.");

  
  
}

document.getElementById("genemail").onclick = processForm(){
 // alert("Just finished loading the webpage in the window.");
  var firstname = document.getElementById("fname").value;
  var lastname = document.getElementById("lname").value;

  console.log(firstname + " " + lastname);

  var label = document.getElementsByClassName("outputArea");

  label[0].innerHTML = "Your Email Address: " + firstname + "." + lastname + "@gmail.com";
  
  document.getElementById("by-line").innerHTML = document.getElementById("by-line").innerHTML + " / Created By: Tony Vance";
}

document.getElementById("genemail").addEventListener("click", processForm, false);
function processForm(){
 alert("Just finished loading the webpage in the window.");
   var firstname = document.getElementById("fname").value;
  var lastname = document.getElementById("lname").value;

  console.log(firstname + " " + lastname);

  var label = document.getElementsByClassName("outputArea");

  label[0].innerHTML = "Your Email Address: " + firstname + "." + lastname + "@gmail.com";
  
  document.getElementById("by-line").innerHTML = document.getElementById("by-line").innerHTML + " / Created By: Tony Vance";
}

---

行

document.getElementById（“genemail”）.onclick=processForm（）{

是问题所在，您不能在此处命名函数

processForm

。如果您将其更改为关键字

function

，则效果很好，请参阅此提琴：

如果您想将函数直接分配给

onclick

事件，则应使用匿名函数：

document.getElementById("genemail").onclick = function(){
 // alert("Just finished loading the webpage in the window.");
  var firstname = document.getElementById("fname").value;
  var lastname = document.getElementById("lname").value;

  console.log(firstname + " " + lastname);

  var label = document.getElementsByClassName("outputArea");

  label[0].innerHTML = "Your Email Address: " + firstname + "." + lastname + "@gmail.com";
  
  document.getElementById("by-line").innerHTML = document.getElementById("by-line").innerHTML + " / Created By: Tony Vance";
}

如果不想使用匿名函数，且函数无参数，则单独定义函数并分配：

function processForm(){
 // alert("Just finished loading the webpage in the window.");
  var firstname = document.getElementById("fname").value;
  var lastname = document.getElementById("lname").value;

  console.log(firstname + " " + lastname);

  var label = document.getElementsByClassName("outputArea");

  label[0].innerHTML = "Your Email Address: " + firstname + "." + lastname + "@gmail.com";
  
  document.getElementById("by-line").innerHTML = document.getElementById("by-line").innerHTML + " / Created By: Tony Vance";
}

document.getElementById("genemail").onclick = processForm; 

---

现在效果很好。谢谢！感谢您的全面回复，现在效果很好！

function processForm(){
 // alert("Just finished loading the webpage in the window.");
  var firstname = document.getElementById("fname").value;
  var lastname = document.getElementById("lname").value;

  console.log(firstname + " " + lastname);

  var label = document.getElementsByClassName("outputArea");

  label[0].innerHTML = "Your Email Address: " + firstname + "." + lastname + "@gmail.com";
  
  document.getElementById("by-line").innerHTML = document.getElementById("by-line").innerHTML + " / Created By: Tony Vance";
}

document.getElementById("genemail").onclick = processForm;