JavaScript: Unescape escaped HTML characters

JavaScript fundamental (ES6 Syntax): Exercise-113 with Solution

Unescape HTML Characters

Write a JavaScript program to unescape escaped HTML characters.

• Use String.prototype.replace() with a regexp that matches the characters that need to be unescaped.
• Use the function's callback to replace each escaped character instance with its associated unescaped character using a dictionary (object).

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2

// Define the 'unescapeHTML' function.
const unescapeHTML = str =>
  // Use 'String.replace' with a regular expression to replace HTML escape characters.
  str.replace(
    /&|<|>|'|"/g,
    // Use an object to map escape characters to their corresponding symbols.
    tag =>
      ({
        '&': '&',
        '<': '<',
        '>': '>',
        '\'': '\'',
        '"': '"'
      }[tag] || tag)
  );

// Test the 'unescapeHTML' function with a sample HTML string.
console.log(unescapeHTML('<a href="#">Me & you</a>'));
// Output: '<a href="#">Me & you</a>'

Output:

"<a href=\"#\">Me & you</a>"

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-113-1 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript program that converts escaped HTML entities in a string back to their original characters.
• Write a JavaScript function that replaces common HTML escape sequences (e.g., <, >) with their literal counterparts.
• Write a JavaScript program that processes a string containing HTML entities and returns the unescaped text.

Improve this sample solution and post your code through Disqus

Previous: Write a JavaScript program to unflatten an object with the paths for keys.
Next: Write a JavaScript program to uncurry a function up to depth n.