JavaScript错误：未捕获的TypeError：无法读取未定义的属性“删除”

Question

我已经创建了一个模态窗口，其中我可以一个一个地打开两个模态窗口，并且它具有类似地一个一个地关闭它们的功能（关闭第二个窗口可使先前的窗口保持活动状态）

（我将代码段中的所有代码都包含在内）

let open_modals = [];

$(function () {

  // Get the button that opens the modal
  // read all the control of any type which has class as modal-button
  var btn = document.querySelectorAll(".modal-button");

  // All page modals
  var modals = document.querySelectorAll('.modal');

  // Get the <span> element that closes the modal
  var spans = document.getElementsByClassName("close");

  // When the user clicks the button, open the modal
  for (var i = 0; i < btn.length; i++) {
    btn[i].onclick = function (e) {
      e.preventDefault();
      modal = document.querySelector(e.target.getAttribute("href"));
      modal.style.display = "block";
      open_modals.push(modal.id);
    }
  }

  // When the user clicks on <span> (x), close the modal
  for (var i = 0; i < spans.length; i++) {
    spans[i].onclick = function () {
      for (var index in modals) {
        if (typeof modals[index].style !== 'undefined' && modals[index].id == open_modals[open_modals.length - 1]) {
          modals[index].style.display = "none";
          open_modals.pop();

          setTimeout(function () {
            for (var index in modals) {
              modals[index].classList.remove("modal-content-active");
              modal.style.display = "none";
              open_modals.pop();
            }
          }, 400);
        }
      }
    }
  }

  // When the user clicks anywhere outside of the modal, close it
  window.onclick = function (event) {
    if (event.target.classList.contains('modal')) {
      for (var index in modals) {
        if (typeof modals[index].style !== 'undefined' && modals[index].id == open_modals[open_modals.length - 1]) {
          modals[index].style.display = "none";
          open_modals.pop();

          setTimeout(function () {
            for (var index in modals) {
              modals[index].classList.remove("modal-content-active");
              modal.style.display = "none";
              open_modals.pop();
            }
          }, 400);
        }
      }
    }
  }
})

@import url('https://fonts.googleapis.com/css?family=Quicksand&display=swap');

/* The Modal (background) */

.modal {
  box-sizing: border-box;
  font-family: 'Quicksand', sans-serif;
  display: none;
  /* Hidden by default */
  position: fixed;
  /* Stay in place */
  z-index: 1;
  /* Sit on top */
  padding-top: 0.1875em;
  /* Location of the box */
  left: 0;
  top: 0;
  width: 100%;
  /* Full width */
  height: 100%;
  /* Full height */
  overflow: auto;
  /* Enable scroll if needed */
  background-color: rgb(0, 0, 0);
  /* Fallback color */
  background-color: rgba(0, 0, 0, 0.4);
  /* Black w/ opacity */
}


/* Modal Content */

.modal-content {
  color: white;
  position: relative;
  background-color: #171B20;
  margin: auto;
  padding: 0;
  border: 0.0625em solid #888;
  width: 97%;
  box-shadow: 0 0.25em 0.5em 0 rgba(0, 0, 0, 0.2), 0 0.375em 1.25em 0 rgba(0, 0, 0, 0.19);
  -webkit-animation-name: animatetop;
  -webkit-animation-duration: 0.4s;
  animation-name: animatetop;
  animation-duration: 0.4s;
}


/* Add Animation */

@-webkit-keyframes animatetop {
  from {
    top: -300px;
    opacity: 0;
  }
  to {
    top: 0;
    opacity: 1;
  }
}

@keyframes animatetop {
  from {
    top: -300px;
    opacity: 0;
  }
  to {
    top: 0;
    opacity: 1;
  }
}

@-webkit-keyframes animateBottom {
  from {
    top: 0px;
    opacity: 1;
  }
  to {
    top: 500px;
    opacity: 0;
  }
}

@keyframes animateBottom {
  from {
    top: 0px;
    opacity: 1;
  }
  to {
    top: 300px;
    opacity: 0;
  }
}

.modal-content-active {
  -webkit-animation-name: animateBottom;
  -webkit-animation-duration: 0.4s;
  animation-name: animateBottom;
  animation-duration: 0.4s;
}


/* The Close Button */

.close {
  color: #F0B823;
  float: right;
  font-size: 9vw;
  font-weight: bold;
  position: absolute;
  right: 0.25em;
  top: -0.25em;
}

.close:hover,
.close:focus {
  color: #fff;
  text-decoration: none;
  cursor: pointer;
}

.modal-header {
  padding: 0.125em 1em;
  background-color: #171B20;
  color: #F0B823;
}

.modal-body {}

.modal-button {
  font-family: 'Quicksand', sans-serif;
  background-color: #171B20;
  border: none;
  color: white;
  padding: 0.248em 0.496em;
  text-align: left;
  text-decoration: none;
  display: inline-block;
  font-size: 7vw;
  margin: 0.124em 0.062em;
  -webkit-transition-duration: 0.4s;
  /* Safari */
  transition-duration: 0;
  cursor: pointer;
  width: auto;
}

.modal-button:hover {
  background-color: #171B20;
  color: #F0B823;
}

.pic {
  margin: auto;
  display: block;
  height: auto;
  width: 50vh;
}

.headertext {
  font-family: 'Quicksand', sans-serif;
  display: block;
  text-align: center;
  font-size: 6.50vw;
}

.bodytext {
  font-size: 3.90vw;
  font-family: 'Quicksand', sans-serif;
  display: block;
  padding: 0.625em 0.9375em;
}

p {
  display: block;
  margin: 0;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<!-- Trigger/Open The Modal -->
<a href="#myModal1" class="modal-button">• Click Me</a>
<!-- The Modal -->
<div id="myModal1" class="modal">
  <!-- Modal content -->
  <div class="modal-content">
    <div class="modal-header">
      <span class="close">×</span>
      <div class="headertext">
        <p>Modal Header</p>
      </div>
    </div>
    <div class="modal-body">
      <img class="pic" src="https://drive.google.com/thumbnail?id=108ZLeoIfNkKODfRbLuPWpmXRl0gH9qkD">
      <div class="bodytext">
        <h2 class="modal-button" href="#myModal2">Enable Second Modal Window by tapping on this text</h2>
      </div>
    </div>
  </div>
</div>
<div id="myModal2" class="modal">
  <!-- Modal content -->
  <div class="modal-content">
    <div class="modal-header">
      <span class="close">×</span>
      <div class="headertext">
        <p>Modal Header 2</p>
      </div>
    </div>
    <div class="modal-body">
      <img class="pic" src="https://drive.google.com/thumbnail?id=108ZLeoIfNkKODfRbLuPWpmXRl0gH9qkD">
      <div class="bodytext">
        <h2 class="modal-button" href="#myModal2">You have opened modal window no.2</h2>
      </div>
    </div>
  </div>
</div>

加载后尝试关闭模式窗口，在控制台输出中出现问题标题中提到的错误

[在另一个音符上 从JavaScript代码底部删除这些行（两次）可解决问题]

setTimeout(function () {
            for (var index in modals) {
              modals[index].classList.remove("modal-content-active");
              modal.style.display = "none";
              open_modals.pop();
            }
          }, 400);

但这部分是动画，我不能跳过 希望有人可以为此提出建议

预先感谢

Answer 1

let open_modals = [];

$(function () {

  // Get the button that opens the modal
  // read all the control of any type which has class as modal-button
  var btn = document.querySelectorAll(".modal-button");

  // All page modals
  var modals = document.querySelectorAll('.modal');

  // Get the <span> element that closes the modal
  var spans = document.getElementsByClassName("close");

  // When the user clicks the button, open the modal
  for (var i = 0; i < btn.length; i++) {
    btn[i].onclick = function (e) {
      e.preventDefault();
      modal = document.querySelector(e.target.getAttribute("href"));
      modal.style.display = "block";
      open_modals.push(modal.id);
    }
  }

  // When the user clicks on <span> (x), close the modal
  for (var i = 0; i < spans.length; i++) {
    spans[i].onclick = function () {
      for (var index in modals) {
        if (typeof modals[index].style !== 'undefined' && modals[index].id == open_modals[open_modals.length - 1]) {
          modals[index].classList.add("modal-content-active");
          var item = modals[index];
          setTimeout(function () {
            item.classList.remove("modal-content-active");
            item.style.display = "none";
            open_modals.pop();

          }, 400);
        }
      }
    }
  }

  //   When the user clicks anywhere outside of the modal, close it
  window.onclick = function (event) {
    if (event.target.classList.contains('modal')) {
      for (var index in modals) {
        if (typeof modals[index].style !== 'undefined' && modals[index].id == open_modals[open_modals.length - 1]) {
          modals[index].classList.add("modal-content-active");
          var item = modals[index];
          setTimeout(function () {

            item.classList.remove("modal-content-active");
            item.style.display = "none";
            open_modals.pop();

          }, 400);

        }
      }
    }
  }
})