armo-palindrome/index.js

Palindrome detector

module.exports = Phrase;

// Adds reverse for all strings
String.prototype.reverse = function() {
  return Array.from(this).reverse().join("");
}

// Defines a Phrase object
function Phrase(content) {
  this.content = content;

  // Returns content processed for palindrome testing
  this.processedContent = function processedContent() {
    return this.letters().toLowerCase();
  }

// Returns the letters in the content
  this.letters = function letters() {
    const lettersRegex = /[a-z]/gi;

    return ( this.content.match(lettersRegex) || [] ).join("");
  }

  // Returns true for a palindrome
  this.palindrome = function palindrome() {
    if ( this.processedContent() ) {
      return this.processedContent() === this.processedContent().reverse();
    } else {
      return false;
    }
  }
}