为什么 Bootstrap 4 中的列高度相等，而不是 Bootstrap 3 中的列？

Question

考虑这些基本且相同的 Bootstrap 3 和 Bootstrap 4 个样本。在同一行内时，in Bootstrap 3 divA 似乎根据其自身的内容需要尽可能多的垂直 space，而 in Bootstrap 4 divA垂直跨度与 divB 一样高取决于其内容。

在 Bootstrap 3 中有没有办法让 divA 像在 v4+ 中那样工作？如何使同一行内的两个 div 具有相同（不固定）的高度？

我已经阅读了 Bootstrap 4+ 中的断点更改，但我找不到任何关于为什么这些工作方式不同的信息。

我是不是漏掉了什么？

#divA {
  background-color: red;
  border: 1px solid black;
}

#divB {
  border: 1px solid black;
}

<head>
  <!-- Required meta tags -->
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

  <!-- Bootstrap CSS -->
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
</head>

<body>
  <div class="container">
    <div class="row">
      <div class="col-xs-6" id="divA">
        <span>B</span>
      </div>
      <div class="col-xs-6" id="divB">
        <div>B</div>
        <div>B</div>
        <div>B</div>
        <div>B</div>
        <div>B</div>
        <div>B</div>
        <div>B</div>
      </div>
    </div>
  </div>

  <!-- Optional JavaScript -->
  <!-- jQuery first, then Popper.js, then Bootstrap JS -->
  <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</body>

#divA {
  background-color: red;
  border: 1px solid black;
}

#divB {
  border: 1px solid black;
}

<head>
  <!-- Required meta tags -->
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

  <!-- Bootstrap CSS -->
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
</head>

<body>
  <div class="container">
    <div class="row">
      <div class="col-sm-6" id="divA">
        <span>B</span>
      </div>
      <div class="col-sm-6" id="divB">
        <div>B</div>
        <div>B</div>
        <div>B</div>
        <div>B</div>
        <div>B</div>
        <div>B</div>
        <div>B</div>
      </div>
    </div>
  </div>

  <!-- Optional JavaScript -->
  <!-- jQuery first, then Popper.js, then Bootstrap JS -->
  <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</body>

Answer 1

只需使用 flex。

.d-flex {
  display: flex;
}
.a {
  background: red;
  width: 30%;
}

<div class="d-flex">
  <div class="a">A</div>
  <div class="b">
    Lorem ipsum dolor sit amet consectetur adipisicing elit. Nulla soluta corporis, repellat architecto error voluptatibus neque vitae tempora laudantium saepe nostrum sint ipsam dignissimos recusandae magnam illo eveniet veritatis! Unde.
  </div>
</div>

为什么 Bootstrap 4 中的列高度相等，而不是 Bootstrap 3 中的列？

Why are columns equal height in Bootstrap 4 and not in Bootstrap 3?

html

css

frontend

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