ee1e8abd87
* 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>
98 lines
1.5 KiB
Markdown
98 lines
1.5 KiB
Markdown
---
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id: 56533eb9ac21ba0edf2244af
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title: 复合赋值之 +=
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challengeType: 1
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videoUrl: 'https://scrimba.com/c/cDR6LCb'
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forumTopicId: 16661
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dashedName: compound-assignment-with-augmented-addition
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---
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# --description--
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在编程当中，通常通过赋值来修改变量的内容。记住，赋值时 Javascript 会先计算`=`右边的内容，所以我们可以写这样的语句：
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`myVar = myVar + 5;`
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以上是最常见的运算赋值语句，即先运算、再赋值。还有一类操作符是一步到位既做运算也赋值的。
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其中一种就是`+=`运算符。
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```js
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var myVar = 1;
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myVar += 5;
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console.log(myVar); // Returns 6
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```
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# --instructions--
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使用`+=`操作符实现同样的效果。
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# --hints--
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`a`应该等于`15`。
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```js
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assert(a === 15);
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```
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`b`应该等于`26`。
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```js
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assert(b === 26);
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```
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`c`应该等于`19`。
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```js
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assert(c === 19);
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```
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你应该对每个变量使用`+=`操作符。
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```js
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assert(code.match(/\+=/g).length === 3);
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```
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不要修改注释上面的代码。
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```js
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assert(
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/var a = 3;/.test(code) &&
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/var b = 17;/.test(code) &&
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/var c = 12;/.test(code)
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);
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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(a,b,c){ return "a = " + a + ", b = " + b + ", c = " + c; })(a,b,c);
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```
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## --seed-contents--
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```js
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var a = 3;
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var b = 17;
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var c = 12;
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// Only change code below this line
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a = a + 12;
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b = 9 + b;
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c = c + 7;
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```
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# --solutions--
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```js
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var a = 3;
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var b = 17;
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var c = 12;
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a += 12;
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b += 9;
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c += 7;
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```
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