Build a RegEx Sandbox - Build a RegEx Sandbox

JavaScript
1

Tell us what’s happening:

Hello,
I am having trouble with this assignment because sometimes, the regex pattern matches part of the html span tags. I am unsure of the best way to fix this. Any assistance would be appreciated. Thank you!

Your code so far

<!-- file: index.html -->
<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="styles.css">
    <title>Regex Sandbox</title>

</head>

<body>
    <h1>Regex Sandbox</h1>
    <main>
        <div id="regex-container">
            <label for="pattern">Regex Pattern:
                <div id="pattern-container">/<input type="text" id="pattern" name="pattern"
                        placeholder="Enter your regex pattern">/</div>
            </label>
            <div id="flags-container">
                <p>Flags: </p>
                <label for="i">
                    <input type="checkbox" name="flags" id="i"> i
                </label>
                <label for="g">
                    <input type="checkbox" name="flags" id="g"> g
                </label>
            </div>
        </div>
        <div id="test-container">
            <p>Test String:</p>
            <div id="test-string" placeholder="Enter your test string" contenteditable="true"></div>
        </div>
        <button class="btn" id="test-btn" type="button">Test Regex</button>
        <div id="result-container">
            <h2>Result:</h2>
            <p id="result">
            </p>
        </div>

    </main>
    <script src="script.js"></script>
</body>

</html>

/* file: styles.css */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --dark-grey: #1b1b32;
    --light-grey: #f5f6f7;
    --golden-yellow: #fecc4c;
    --yellow: #ffcc4c;
    --gold: #feac32;
    --orange: #ffac33;
    --dark-orange: #f89808;
    --border: 0.2rem solid darkgrey;
    --padding: 0.3rem;
}

body {
    background-color: var(--dark-grey);
    color: var(--light-grey);
    font-size: 20px;
    font-family: "Lato", Helvetica, Arial, sans-serif;
    padding: 5px;
}

h1 {
    margin: 5rem auto 2rem;
    text-align: center;
}

p {
    padding: var(--padding);
}

#regex-container {
    max-width: 680px;
    margin: 20px auto;
    display: flex;
    justify-content: center;
    align-items: center;
    border: var(--border);
}

#regex-container>label {
    padding: var(--padding);
    flex: 1 1 auto;
}

#pattern-container {
    display: inline-block;
    color: var(--dark-grey);
    background-color: var(--light-grey);
    margin: 5px;
    border: var(--border);
}

#pattern {
    margin: 0.2rem;
    border: 0;
    font-size: 1rem;
    width: calc(100% - 1.2rem);
}

#pattern:focus {
    outline: none;
}

#flags-container {
    display: flex;
    align-items: center;
    flex: 1 1 auto;
}

#flags-container>label {
    padding: var(--padding);
    margin-right: 0.3rem;
}

#test-container {
    max-width: 680px;
    margin: 20px auto;
    display: flex;
    flex-direction: column;
    flex: 0 0 auto;
    border: var(--border);
}

#test-string {
    background-color: var(--light-grey);
    min-height: 5rem;
    color: var(--dark-grey);
    border-top: var(--border);
    font-size: 1.2rem;
}

[contenteditable=true]:empty:before {
    content: attr(placeholder);
    pointer-events: none;
    color: var(--dark-grey);
}

::placeholder {
    color: var(--dark-grey);
}


button {
    display: block;
    cursor: pointer;
    width: 8rem;
    margin: 0.2rem auto;
    color: var(--dark-grey);
    background-color: var(--gold);
    background-image: linear-gradient(var(--golden-yellow), var(--orange));
    border-color: var(--gold);
    border-width: 0.2rem;
    font-size: 1.1rem;
}

.btn:hover {
    background-image: linear-gradient(var(--yellow), var(--dark-orange));
}

#result-container {
    max-width: 680px;
    margin: 20px auto;
    display: flex;
    justify-content: center;
    align-items: center;
}

h2 {
    align-self: flex-start;
    margin: 0.4rem 0.2rem 0.2rem;
    flex: 0 1 auto;
}

#result {
    color: var(--dark-grey);
    background-color: var(--light-grey);
    font-size: 1.5rem;
    flex: 1 1 auto;
    margin: 0.2rem;
    border: var(--border);
    min-height: 3rem;
}

.highlight {
    background-color: lightgreen;
}

/* file: script.js */
const regexPattern = document.getElementById('pattern');
const stringToTest = document.getElementById('test-string');
const testButton = document.getElementById('test-btn');
const testResult = document.getElementById('result');

const caseInsensitiveFlag = document.getElementById('i');
const globalFlag = document.getElementById('g');

function getFlags() {
  let flagStr = '';
  console.log(flagStr);
  if (caseInsensitiveFlag.checked === true) {
    flagStr = flagStr + 'i';
  }
  if (globalFlag.checked === true) {
    flagStr = flagStr + 'g';
  }
  return flagStr;
}

function getRegex() {
  let regex = new RegExp(regexPattern.value, getFlags());
  console.log(regex);
  return regex;
}

function getMatches() {
  let test = stringToTest.textContent;
  console.log(test);
  let regex = getRegex();
  let matches = test.match(regex);
  console.log(matches);
  if (test === "" | matches === null) {
    testResult.textContent = 'no match'
  }
  else {
    for (const match of matches) {
      console.log(match);
      test = test.replace(match, `<span class="highlight">${match}</span>`);
    }
  }
  stringToTest.innerHTML = test;
  console.log(test);
  testResult.textContent = matches.join(", ");
}


testButton.addEventListener('click', getMatches);

Your browser information:

User Agent is: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.0.0 Safari/537.36

Challenge Information:

Build a RegEx Sandbox - Build a RegEx Sandbox

2

What should the first argument be in the replace method?

Working with Regular Expressions - How Can You Match and Replace All Occurrences in a String? | Learn | freeCodeCamp.org

3

I thought it should be match, since it’s going through each match of the array. I thought about removing the for…of and just using .replace with regex as the first argument, but I don’t know how I would put the value of the match in the second argument.

4

Try just doing this and leaving everything else “as is”. Then test in the preview window.

5

It still does the same thing. The test string still shows up with bits and pieces of span tags if the regex pattern matches anything in them

6

Please post your updated code.

7 
const regexPattern = document.getElementById('pattern');
const stringToTest = document.getElementById('test-string');
const testButton = document.getElementById('test-btn');
const testResult = document.getElementById('result');

const caseInsensitiveFlag = document.getElementById('i');
const globalFlag = document.getElementById('g');

function getFlags() {
  let flagStr = '';
  console.log(flagStr);
  if (caseInsensitiveFlag.checked === true) {
    flagStr = flagStr + 'i';
  }
  if (globalFlag.checked === true) {
    flagStr = flagStr + 'g';
  }
  return flagStr;
}

function getRegex() {
  let regex = new RegExp(regexPattern.value, getFlags());
  console.log(regex);
  return regex;
}

function getMatches() {
  let test = stringToTest.textContent;
  console.log(test);
  let regex = getRegex();
  let matches = test.match(regex);
  console.log(matches);
  if (test === "" | matches === null) {
    testResult.textContent = 'no match'
  }
  else {
    for (const match of matches) {
      console.log(match);
      test = test.replace(regex, `<span class="highlight">${match}</span>`);
    }
  }
  stringToTest.innerHTML = test;
  console.log(test);
  testResult.textContent = matches.join(", ");
}


testButton.addEventListener('click', getMatches);
8

I got it working by removing the for…of and using $& instead of ${match}. Thank you!

1 Like
9

Nicely done. And I just learned another way of doing this from you. Thank you!

10

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