<a>标签上的onclick事件需要点击两次

Question

为什么我需要在我的“a”标签上点击两次来运行 onclick 事件？我的目标：当“a”标签被点击时，显示为块下面默认隐藏的div。function myFunction1(num) {  var x = document.getElementById("description");  if (x.style.display === "none") {    x.style.display = "block";  } else {    x.style.display = "none";;  }}function myFunction2(num) {  var x = document.getElementById("benefits");  if (x.style.display === "none") {    x.style.display = "block";  } else {    x.style.display = "none";;    return  }}function myFunction(button) {  var x = button.id;  switch (x) {    case '1':      myFunction1(x);      break;    case '2':      myFunction4(x);      break;    default:      return false;  }}var buttons = document.getElementsByTagName('a');for (var i = 0, len = buttons.length; i < len; i++) {  buttons[i].onclick = function() {    myFunction(this);  }};<header class="container">  <nav class="navbar">    <a id="1">Description</a>    <a id="2">Benefits</a>  </nav></header><div class="details">  <div class="details_object" id="description" style="display: none">    <p> <span></span> Lorem ipsum dolor sit, amet consectetur adipisicing elit. Illo, dolorem. </p>    <p> <span></span> Lorem ipsum dolor sit, amet consectetur adipisicing elit. Illo, dolorem. </p>  </div>  <div class="details_object" id="benefits" style="display: none">    <p> <span></span> Lorem ipsum dolor sit, amet consectetur adipisicing elit. Illo, dolorem. </p>    <p> <span></span> Lorem ipsum dolor sit, amet consectetur adipisicing elit. Illo, dolorem. </p>  </div>我还尝试实现的是一次只显示一个 .details_object，所以如果显示了一个，但调用了另一个函数，请将第一个设置为默认值。

Answer 1

我会稍微更改您的 html，以便您可以使用链接的 href 属性，然后只有一个函数来显示和隐藏相关的 div，而不是每个链接的函数（js 中的注释解释了我所做的事情）：

var divs = document.getElementsByClassName('details_object'); // get all the detail divs

var buttons = document.getElementsByTagName('a'); // get all the links

for (var i = 0, len = buttons.length; i < len; i++) {

  buttons[i].addEventListener("click", function(e) { // bind your click to the buttons (pass the event into the function)

    e.preventDefault(); // stop the default click event of the anchor

    for (var j = 0; j < divs.length; j++) {

      if (divs[j].id === e.currentTarget.hash.substr(1)) { // compare the id of the div with the hash value of the link href (minus the #)

        divs[j].style.display = 'block'; // if they match - show the div

        buttons[j].classList.add('highlight');

      } else {

        divs[j].style.display = 'none'; // if they don't match - hide the div

        buttons[j].classList.remove('highlight');

      }

    }

  });

};

.highlight {

  background: green;

}

<header class="container">

  <nav class="navbar">

    <a id="1" href="#description">Description</a>

    <a id="2" href="#benefits">Benefits</a>

  </nav>

</header>

<div class="details">

  <div class="details_object" id="description" style="display: none">

    description

    <p> <span></span> Lorem ipsum dolor sit, amet consectetur adipisicing elit. Illo, dolorem. </p>

    <p> <span></span> Lorem ipsum dolor sit, amet consectetur adipisicing elit. Illo, dolorem. </p>

  </div>

  <div class="details_object" id="benefits" style="display: none">

    benefits

    <p> <span></span> Lorem ipsum dolor sit, amet consectetur adipisicing elit. Illo, dolorem. </p>

    <p> <span></span> Lorem ipsum dolor sit, amet consectetur adipisicing elit. Illo, dolorem. </p>

  </div>

</div>

Answer 2

您可以使用 Javascript 的innerHTML属性使其更优化和更容易。您可以从此处了解更多信息。

function myFunction1 (num) {

    document.getElementById("description").innerHTML= "Description paragraph";

}

function myFunction2 (num) {

    document.getElementById("description").innerHTML= "Benefits paragraph";    

}

function myFunction (button) {

    var x = button.id;

    switch (x) {

        case '1':

            myFunction1(x);

            break;

        case '2':

            myFunction2(x);

            break;

        default:

            return false;

    }

}

var buttons = document.getElementsByTagName('a');

for (var i = 0, len = buttons.length; i < len; i++) {

    buttons[i].onclick = function (){

        myFunction (this);

    }};

<header class="container">

    <nav class="navbar">

        <a id="1">Description</a>

        <a id="2">Benefits</a>        

    </nav> 

</header>

<div class="details">

    <div class="details_object"  id="description"/>

    <div class="details_object"  id="benefits" />

       

 </div>