如果只有一列，Flexbox会将列对齐到右侧

Question

我有两列flexbox布局。但是，有时只有一列，在这种情况下，列应该向右对齐。目前，该列与左侧对齐。

https://codepen.io/sleepydada/pen/rzVRxL

HTML：

<div class="answers">
  <div class="answer">first answer</div>
  <div class="answer">second answer</div>
</div>
<div class="answers">
  <div class="answer">first answer</div>
</div>

SCSS：

* {
  box-sizing: border-box;
}

.answers {
  border: 2px solid black;
  margin-bottom: 20px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;

  &:first-of-type {
    background: #ccc;
  }

  .answer {
    background: crimson;
    margin: 20px 0;
    border: 1px solid blue;
    flex: 0 0 33.3333%;
  }
}   

Answer 1

您可以添加此CSS：

.answer:only-of-type {
  margin-left: auto;
}

来自MDN

  

：only-of-type CSS伪类表示没有的元素   同类型的兄弟姐妹。

codepen

＆＃13;

＆＃13;

* {
  box-sizing: border-box;
}

.answers {
  border: 2px solid black;
  margin-bottom: 20px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
}

.answers:first-of-type {
  background: #ccc;
}

.answers .answer {
  background: crimson;
  margin: 20px 0;
  border: 1px solid blue;
  flex: 0 0 33.3333%;
}

.answers .answer:only-of-type {
  margin-left: auto;
}

＆＃13;

<div class="answers">
  <div class="answer">first answer</div>
  <div class="answer">second answer</div>
</div>
<div class="answers">
  <div class="answer">first answer</div>
</div>

＆＃13;

＆＃13;

＆＃13;

Answer 2

您可以添加一个height设置为0

的不可见div

* {
  box-sizing: border-box;
}

.invisible {
  height: 0;
  border: none !important;
}

.answers {
  border: 2px solid black;
  margin-bottom: 20px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
}
.answers:first-of-type {
  background: #ccc;
}
.answers .answer {
  background: crimson;
  margin: 20px 0;
  border: 1px solid blue;
  flex: 0 0 33.3333%;
}

<div class="answers">
  <div class="answer">first answer</div>
  <div class="answer invisible"><!--invisible div--></div>
  <div class="answer">second answer</div>
</div>
<div class="answers">
  <div class="answer invisible"><!--invisible div--></div>
  <div class="answer">first answer</div>
</div>