73 lines
1.7 KiB
Markdown
73 lines
1.7 KiB
Markdown
---
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id: 56533eb9ac21ba0edf2244b5
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title: 转义字符串中的引号
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challengeType: 1
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videoUrl: 'https://scrimba.com/c/c2QvgSr'
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forumTopicId: 17568
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dashedName: escaping-literal-quotes-in-strings
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---
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# --description--
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定义一个字符串必须要用单引号或双引号来包裹它。 那么当你的字符串里面包含引号 `"` 或者 `'` 时该怎么办呢?
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在 JavaScript 中，可以通过在引号前面使用<dfn>反斜杠</dfn>（`\`）来<dfn>转义</dfn>引号。
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```js
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var sampleStr = "Alan said, \"Peter is learning JavaScript\".";
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```
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有了转义符号，JavaScript 就知道这个单引号或双引号并不是字符串的结尾，而是字符串内的字符。 所以，上面的字符串打印到控制台的结果为：
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```js
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Alan said, "Peter is learning JavaScript".
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```
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# --instructions--
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使用<dfn>反斜杠</dfn>给 `myStr` 变量赋值一个字符串，这样如果你要打印它到控制台，将会看到：
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```js
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I am a "double quoted" string inside "double quotes".
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```
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# --hints--
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你的代码中应该包含两个双引号（`"`）以及四个转义的双引号（`\"`）。
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```js
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assert(code.match(/\\"/g).length === 4 && code.match(/[^\\]"/g).length === 2);
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```
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变量 myStr 应该包含字符串 `I am a "double quoted" string inside "double quotes".`
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```js
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assert(/I am a "double quoted" string inside "double quotes(\."|"\.)$/.test(myStr));
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```
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# --seed--
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## --after-user-code--
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```js
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(function(){
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if(typeof myStr === 'string') {
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console.log("myStr = \"" + myStr + "\"");
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} else {
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console.log("myStr is undefined");
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}
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})();
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```
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## --seed-contents--
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```js
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var myStr = ""; // Change this line
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```
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# --solutions--
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```js
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var myStr = "I am a \"double quoted\" string inside \"double quotes\".";
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```
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