Bootstrap 4容器的文本包装

我知道你的问题,基本上,你使用标签是不正确的。

Element div not allowed as child of element span/h1 in this context.

检查小提琴链接,它解决了您的问题。 Fiddle

<div class="row px-3">
    <div class="jumbotron">
        <div class="float-right">
            <div class="">Submitted                   by
            </div>
            <div class="btn-group">
                <button class="btn">User</button>
                <button class="btn btn-info"></button>
                <button class="btn btn-danger"></button>
            </div>
        </div>
    <p id="editor-title">A very long post title that   needs to be long enough to see if the wrapping is working or not sdjfs dakjsd askjdhas dkjashd asdjkhasd askjdhas dasjdasdkjasd asdkjhasd djkf dfuieywrbewrgew weruwe</p>
    <div id="editor-body">a short body underneath the   title</div>
    </div>
</div>

我建议您使用W3C HTML检查器。