--- title: Convert HTML Entities --- # Convert HTML Entities ![HTML entities &'<>"](//discourse-user-assets.s3.amazonaws.com/original/2X/f/fc44d1dfbd3910e574cdedb0f05162f65b4cb7c4.jpg) ![:triangular_flag_on_post:](https://forum.freecodecamp.com/images/emoji/emoji_one/triangular_flag_on_post.png?v=3 ":triangular_flag_on_post:") Remember to use **`Read-Search-Ask`** if you get stuck. Try to pair program ![:busts_in_silhouette:](https://forum.freecodecamp.com/images/emoji/emoji_one/busts_in_silhouette.png?v=3 ":busts_in_silhouette:") and write your own code ![:pencil:](https://forum.freecodecamp.com/images/emoji/emoji_one/pencil.png?v=3 ":pencil:") ### ![:checkered_flag:](https://forum.freecodecamp.com/images/emoji/emoji_one/checkered_flag.png?v=3 ":checkered_flag:") Problem Explanation: * You have to create a program that will convert HTML entities from string to their corresponding HTML entities. There are only a few so you can use different methods. ## ![:speech_balloon:](https://forum.freecodecamp.com/images/emoji/emoji_one/speech_balloon.png?v=3 ":speech_balloon:") Hint: 1 * You can use regular Expressions however I didn't in this case. > _try to solve the problem now_ ## ![:speech_balloon:](https://forum.freecodecamp.com/images/emoji/emoji_one/speech_balloon.png?v=3 ":speech_balloon:") Hint: 2 * You will benefit from a chart with all the html entities so you know which ones are the right ones to put. > _try to solve the problem now_ ## ![:speech_balloon:](https://forum.freecodecamp.com/images/emoji/emoji_one/speech_balloon.png?v=3 ":speech_balloon:") Hint: 3 * You should separate the string and work with each character to convert the right ones and then join everything back up. > _try to solve the problem now_ ## Spoiler Alert! ![warning sign](//discourse-user-assets.s3.amazonaws.com/original/2X/2/2d6c412a50797771301e7ceabd554cef4edcd74d.gif) **Solution ahead!** ## ![:beginner:](https://forum.freecodecamp.com/images/emoji/emoji_one/beginner.png?v=3 ":beginner:") Basic Code Solution: ```javascript function convertHTML(str) { // Split by character to avoid problems. var temp = str.split(''); // Since we are only checking for a few HTML elements, use a switch for (var i = 0; i < temp.length; i++) { switch (temp[i]) { case '<': temp[i] = '<'; break; case '&': temp[i] = '&'; break; case '>': temp[i] = '>'; break; case '"': temp[i] = '"'; break; case "'": temp[i] = "'"; break; } } temp = temp.join(''); return temp; } //test here convertHTML("Dolce & Gabbana"); ``` ### Code Explanation: * Assign **temp** to `str.split('')`, which creates an array containing each individual character in the passed in string. * Pass each character in the newly created array into a `switch()` statement. * Replace the HTML entities with their corresponding HTML entity string (i.e. `'&'` becomes `'&'` in line 51) * `temp.join('')` converts the array of characters into a string to be returned. #### Relevant Links * str.split() * arr.join() * switch statement ## ![:sunflower:](https://forum.freecodecamp.com/images/emoji/emoji_one/sunflower.png?v=3 ":sunflower:") Intermediate Code Solution: ```javascript function convertHTML(str) { // Use Object Lookup to declare as many HTML entities as needed. const htmlEntities = { "&" : '&', "<" : "<", ">" : ">", '"' : """, "'" :"'" } // Using a regex, replace characters with it's corresponding html entity return str.replace(/([&<>\"'])/g, match => htmlEntities[match]); } // test here convertHTML("Dolce & Gabbana"); ``` ### Code Explanation: * Create an object to use the Lookup functionality and easily find the characters. * Use `replace()` to replace characters with regex. * The first argument for `replace()` is a regex that catches all the target characters and puts them into a capturing group. * The second arguments for `replace()` is a function with the matched character as a parameter. It returns the correspondant entity from `htmlEntities`. #### Relevant Links * str.replace() * Regular Expressions ## ![:rotating_light:](https://forum.freecodecamp.com/images/emoji/emoji_one/rotating_light.png?v=3 ":rotating_light:") Advanced Code Solution: ```javascript function convertHTML(str) { // Use Object Lookup to declare as many HTML entities as needed. const htmlEntities={ '&':'&', '<':'<', '>':'>', '"':'"', '\'':"'" }; //Use map function to return a filtered str with all entities changed automatically. return str.split('').map(entity => htmlEntities[entity] || entity).join(''); } // test here convertHTML("Dolce & Gabbana"); ``` ### Code Explanation: * Create an object to use the Lookup functionality and easily find the characters. * Split the original string by characters and use map to check for the changed html entity or use the same one. * The a function is added which is what returns the converted entity or the original one if there is no conversion. * Lastly we join all the characters once again. **Note** that if you went the regex route then you don't need to join anything, just make sure you return the whole operation or save it to a variable and then return it. #### Relevant Links * str.split() * arr.map() * arr.join() ## ![:clipboard:](https://forum.freecodecamp.com/images/emoji/emoji_one/clipboard.png?v=3 ":clipboard:") NOTES FOR CONTRIBUTIONS: * ![:warning:](https://forum.freecodecamp.com/images/emoji/emoji_one/warning.png?v=3 ":warning:") **DO NOT** add solutions that are similar to any existing solutions. If you think it is **_similar but better_**, then try to merge (or replace) the existing similar solution. * Add an explanation of your solution. * Categorize the solution in one of the following categories — **Basic**, **Intermediate** and **Advanced**. ![:traffic_light:](https://forum.freecodecamp.com/images/emoji/emoji_one/traffic_light.png?v=3 ":traffic_light:")