2019-11-05 02:09:40 -01:00
|
|
|
---
|
|
|
|
|
id: 5d792533ed00e75d129e1b18
|
2019-12-09 19:37:02 +09:00
|
|
|
title: Part 013
|
2019-11-05 02:09:40 -01:00
|
|
|
challengeType: 0
|
|
|
|
|
isBeta: true
|
|
|
|
|
---
|
|
|
|
|
|
|
|
|
|
## Description
|
|
|
|
|
<section id='description'>
|
|
|
|
|
|
|
|
|
|
`replace` is a higher order function because it can take a function as argument (higher order functions can also return functions).
|
2019-12-09 19:37:02 +09:00
|
|
|
|
|
|
|
|
Pass the `+` function from `infixToFunction` to the `replace` method as the second argument.
|
|
|
|
|
|
2019-11-05 02:09:40 -01:00
|
|
|
This is how you would pass the `-` function:
|
|
|
|
|
|
|
|
|
|
```js
|
|
|
|
|
str.replace(regex, infixToFunction["-"])
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</section>
|
|
|
|
|
|
|
|
|
|
## Instructions
|
|
|
|
|
<section id='instructions'>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</section>
|
|
|
|
|
|
|
|
|
|
## Tests
|
|
|
|
|
<section id='tests'>
|
|
|
|
|
|
|
|
|
|
```yml
|
|
|
|
|
tests:
|
|
|
|
|
- text: See description above for instructions.
|
|
|
|
|
testString: assert(infixEval("ab", /(a)b/) === "aba");
|
|
|
|
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</section>
|
|
|
|
|
|
|
|
|
|
## Challenge Seed
|
|
|
|
|
<section id='challengeSeed'>
|
|
|
|
|
|
|
|
|
|
<div id='html-seed'>
|
|
|
|
|
|
|
|
|
|
```html
|
|
|
|
|
<script>
|
|
|
|
|
|
|
|
|
|
const infixToFunction = {
|
|
|
|
|
"+": (x, y) => x + y,
|
|
|
|
|
"-": (x, y) => x - y,
|
|
|
|
|
"*": (x, y) => x * y,
|
|
|
|
|
"/": (x, y) => x / y
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
const infixEval = (str, regex) => str.replace(regex, "");
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</script>
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
### Before Test
|
|
|
|
|
<div id='html-setup'>
|
|
|
|
|
|
|
|
|
|
```html
|
|
|
|
|
<!DOCTYPE html>
|
|
|
|
|
<html lang="en">
|
|
|
|
|
<head>
|
|
|
|
|
<meta charset="UTF-8">
|
|
|
|
|
<title>Spreadsheet</title>
|
|
|
|
|
<style>
|
|
|
|
|
#container {
|
|
|
|
|
display: grid;
|
|
|
|
|
grid-template-columns: 50px repeat(10, 200px);
|
|
|
|
|
grid-template-rows: repeat(11, 30px);
|
|
|
|
|
}
|
|
|
|
|
.label {
|
|
|
|
|
background-color: lightgray;
|
|
|
|
|
text-align: center;
|
|
|
|
|
vertical-align: middle;
|
|
|
|
|
line-height: 30px;
|
|
|
|
|
}
|
|
|
|
|
</style>
|
|
|
|
|
</head>
|
|
|
|
|
<body>
|
|
|
|
|
<div id="container">
|
|
|
|
|
<div></div>
|
|
|
|
|
</div>
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
### After Test
|
|
|
|
|
<div id='html-teardown'>
|
|
|
|
|
|
|
|
|
|
```html
|
|
|
|
|
</body>
|
|
|
|
|
</html>
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</section>
|
|
|
|
|
|
|
|
|
|
## Solution
|
|
|
|
|
<section id='solution'>
|
|
|
|
|
|
|
|
|
|
```html
|
|
|
|
|
<script>
|
|
|
|
|
const infixToFunction = {
|
|
|
|
|
"+": (x, y) => x + y,
|
|
|
|
|
"-": (x, y) => x - y,
|
|
|
|
|
"*": (x, y) => x * y,
|
|
|
|
|
"/": (x, y) => x / y
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
const infixEval = (str, regex) => str.replace(regex, infixToFunction["+"]);
|
|
|
|
|
</script>
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
</section>
|
