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freeCodeCamp/curriculum/challenges/chinese/01-responsive-web-design/basic-html-and-html5/add-placeholder-text-to-a-text-field.md
Oliver Eyton-Williams ee1e8abd87 feat(curriculum): restore seed + solution to Chinese (#40683)
* feat(tools): add seed/solution restore script

* chore(curriculum): remove empty sections' markers

* chore(curriculum): add seed + solution to Chinese

* chore: remove old formatter

* fix: update getChallenges

parse translated challenges separately, without reference to the source

* chore(curriculum): add dashedName to English

* chore(curriculum): add dashedName to Chinese

* refactor: remove unused challenge property 'name'

* fix: relax dashedName requirement

* fix: stray tag

Remove stray `pre` tag from challenge file.

Signed-off-by: nhcarrigan <nhcarrigan@gmail.com>

Co-authored-by: nhcarrigan <nhcarrigan@gmail.com>
2021-01-12 19:31:00 -07:00

107 lines
2.2 KiB
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---
id: bad87fee1348bd9aedf08830
title: 给输入框添加占位符文本
challengeType: 0
videoUrl: 'https://scrimba.com/p/pVMPUv/cKdJDhg'
forumTopicId: 16647
dashedName: add-placeholder-text-to-a-text-field
---
# --description--
`Placeholder` 占位符是用户在 `input` 输入框中输入任何东西前的预定义文本。
你可以像这样创建一个占位符:
`<input type="text" placeholder="this is placeholder text">`
**注意:**别忘了 `input` 元素是 "自闭和标签",即不需要结束标签。
# --instructions--
`input` 输入框的 `placeholder` 占位符文本设置为 "cat photo URL"。
# --hints--
给现有的 `input` 输入框添加一个 `placeholder` 属性。
```js
assert($('input[placeholder]').length > 0);
```
设置 `placeholder` 属性的值为 `cat photo URL`
```js
assert(
$('input') &&
$('input').attr('placeholder') &&
$('input')
.attr('placeholder')
.match(/cat\s+photo\s+URL/gi)
);
```
`input` 元素不该有结束标签。
```js
assert(!code.match(/<input.*\/?>.*<\/input>/gi));
```
`input` 输入框的语法必须正确。
```js
assert($('input[type=text]').length > 0);
```
# --seed--
## --seed-contents--
```html
<h2>CatPhotoApp</h2>
<main>
<p>Click here to view more <a href="#">cat photos</a>.</p>
<a href="#"><img src="https://bit.ly/fcc-relaxing-cat" alt="A cute orange cat lying on its back."></a>
<p>Things cats love:</p>
<ul>
<li>cat nip</li>
<li>laser pointers</li>
<li>lasagna</li>
</ul>
<p>Top 3 things cats hate:</p>
<ol>
<li>flea treatment</li>
<li>thunder</li>
<li>other cats</li>
</ol>
<input type="text">
</main>
```
# --solutions--
```html
<h2>CatPhotoApp</h2>
<main>
<p>Click here to view more <a href="#">cat photos</a>.</p>
<a href="#"><img src="https://bit.ly/fcc-relaxing-cat" alt="A cute orange cat lying on its back."></a>
<p>Things cats love:</p>
<ul>
<li>cat nip</li>
<li>laser pointers</li>
<li>lasagna</li>
</ul>
<p>Top 3 things cats hate:</p>
<ol>
<li>flea treatment</li>
<li>thunder</li>
<li>other cats</li>
</ol>
<input type="text" placeholder="cat photo URL">
</main>
```