116 lines
3.9 KiB
Markdown
116 lines
3.9 KiB
Markdown
---
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id: 56533eb9ac21ba0edf2244e0
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title: Replacing If Else Chains with Switch
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challengeType: 1
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---
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## Description
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<section id='description'>
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If you have many options to choose from, a <code>switch</code> statement can be easier to write than many chained <code>if</code>/<code>else if</code> statements. The following:
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<blockquote>if (val === 1) {<br> answer = "a";<br>} else if (val === 2) {<br> answer = "b";<br>} else {<br> answer = "c";<br>}</blockquote>
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can be replaced with:
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<blockquote>switch(val) {<br> case 1:<br> answer = "a";<br> break;<br> case 2:<br> answer = "b";<br> break;<br> default:<br> answer = "c";<br>}</blockquote>
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</section>
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## Instructions
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<section id='instructions'>
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Change the chained <code>if</code>/<code>else if</code> statements into a <code>switch</code> statement.
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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: You should not use any <code>else</code> statements anywhere in the editor
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testString: assert(!/else/g.test(code), 'You should not use any <code>else</code> statements anywhere in the editor');
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- text: You should not use any <code>if</code> statements anywhere in the editor
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testString: assert(!/if/g.test(code), 'You should not use any <code>if</code> statements anywhere in the editor');
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- text: You should have at least four <code>break</code> statements
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testString: assert(code.match(/break/g).length >= 4, 'You should have at least four <code>break</code> statements');
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- text: <code>chainToSwitch("bob")</code> should be "Marley"
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testString: assert(chainToSwitch("bob") === "Marley", '<code>chainToSwitch("bob")</code> should be "Marley"');
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- text: <code>chainToSwitch(42)</code> should be "The Answer"
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testString: assert(chainToSwitch(42) === "The Answer", '<code>chainToSwitch(42)</code> should be "The Answer"');
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- text: "<code>chainToSwitch(1)</code> should be \"There is no #1\""
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testString: "assert(chainToSwitch(1) === \"There is no #1\", '<code>chainToSwitch(1)</code> should be \"There is no #1\"');"
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- text: <code>chainToSwitch(99)</code> should be "Missed me by this much!"
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testString: assert(chainToSwitch(99) === "Missed me by this much!", '<code>chainToSwitch(99)</code> should be "Missed me by this much!"');
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- text: <code>chainToSwitch(7)</code> should be "Ate Nine"
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testString: assert(chainToSwitch(7) === "Ate Nine", '<code>chainToSwitch(7)</code> should be "Ate Nine"');
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- text: <code>chainToSwitch("John")</code> should be "" (empty string)
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testString: assert(chainToSwitch("John") === "", '<code>chainToSwitch("John")</code> should be "" (empty string)');
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- text: <code>chainToSwitch(156)</code> should be "" (empty string)
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testString: assert(chainToSwitch(156) === "", '<code>chainToSwitch(156)</code> should be "" (empty string)');
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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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function chainToSwitch(val) {
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var answer = "";
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// Only change code below this line
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if (val === "bob") {
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answer = "Marley";
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} else if (val === 42) {
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answer = "The Answer";
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} else if (val === 1) {
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answer = "There is no #1";
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} else if (val === 99) {
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answer = "Missed me by this much!";
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} else if (val === 7) {
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answer = "Ate Nine";
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}
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// Only change code above this line
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return answer;
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}
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// Change this value to test
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chainToSwitch(7);
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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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function chainToSwitch(val) {
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var answer = "";
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switch(val) {
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case "bob":
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answer = "Marley";
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break;
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case 42:
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answer = "The Answer";
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break;
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case 1:
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answer = "There is no #1";
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break;
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case 99:
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answer = "Missed me by this much!";
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break;
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case 7:
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answer = "Ate Nine";
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}
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return answer;
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}
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```
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</section>
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