freeCodeCamp/part-025.md at 6ccd0d21a1ab40d2a7ce6d5a3a4ca1bd4d86387f

Randell Dawson b9c9a95223 chore(learn): Renamed all project-based curriculum project step filenames to use 3-digit format of part-ddd.md (#39463 )

* fix: renamed basic html cat photo app steps

* fix: renamed css-variables project steps

* fix: renamed d3-dashboard filenames

* fix: renamed rpg-game filenames

* fix: renamed functional-progamming-spreadsheet filenames

* fix: renamed calorie-counter project filenames

2020-09-16 11:54:12 +05:30

2.3 KiB

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id, title, challengeType, isHidden

id	title	challengeType	isHidden
5d7925346f4f2da6df4354a6	Part 25	0	true

Description

Define an empty function applyFn which takes an argument str. Use the curly brace syntax with an anonymous function. Do not wrap parentheses around the parameter.

Instructions

Tests

tests:
  - text: See description above for instructions.
    testString: assert(code.replace(/\s/g, "").includes("constapplyFn=str=>{}"));

Challenge Seed

<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, (_, arg1, fn, arg2) =>
    infixToFunction[fn](parseFloat(arg1), parseFloat(arg2))
  );

const highPrecedence = str => {
  const regex = /([0-9.]+)([*\/])([0-9.]+)/;
  const str2 = infixEval(str, regex);
  return str === str2 ? str : highPrecedence(str2);
};

const spreadsheetFunctions = {
  "": x => x
};


</script>

Before Test

<!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>

After Test

</body>
</html>

Solution

<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, (_, arg1, fn, arg2) =>
    infixToFunction[fn](parseFloat(arg1), parseFloat(arg2))
  );

const highPrecedence = str => {
  const regex = /([0-9.]+)([*\/])([0-9.]+)/;
  const str2 = infixEval(str, regex);
  return str === str2 ? str : highPrecedence(str2);
};

const spreadsheetFunctions = {
  "": x => x
};

const applyFn = str => {

}
</script>

2.3 KiB Raw Blame History