91 lines
1.6 KiB
Markdown
91 lines
1.6 KiB
Markdown
---
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id: 56533eb9ac21ba0edf2244b0
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title: Compound Assignment With Augmented Subtraction
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challengeType: 1
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videoUrl: 'https://scrimba.com/c/c2Qv7AV'
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---
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## Description
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<section id='description'>
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Like the <code>+=</code> operator, <code>-=</code> subtracts a number from a variable.
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<code>myVar = myVar - 5;</code>
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will subtract <code>5</code> from <code>myVar</code>. This can be rewritten as:
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<code>myVar -= 5;</code>
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</section>
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## Instructions
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<section id='instructions'>
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Convert the assignments for <code>a</code>, <code>b</code>, and <code>c</code> to use the <code>-=</code> operator.
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: <code>a</code> should equal <code>5</code>
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testString: assert(a === 5);
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- text: <code>b</code> should equal <code>-6</code>
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testString: assert(b === -6);
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- text: <code>c</code> should equal <code>2</code>
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testString: assert(c === 2);
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- text: You should use the <code>-=</code> operator for each variable
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testString: assert(code.match(/-=/g).length === 3);
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- text: Do not modify the code above the line
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testString: assert(/var a = 11;/.test(code) && /var b = 9;/.test(code) && /var c = 3;/.test(code));
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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```js
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var a = 11;
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var b = 9;
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var c = 3;
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// Only modify code below this line
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a = a - 6;
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b = b - 15;
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c = c - 1;
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```
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</div>
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### After Test
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<div id='js-teardown'>
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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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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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var a = 11;
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var b = 9;
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var c = 3;
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a -= 6;
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b -= 15;
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c -= 1;
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```
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</section>
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