---
title: Convert HTML Entities
---
# Convert HTML Entities
---
## 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.
---
## Hints
### Hint 1
* You can use regular Expressions however I didn't in this case.
### Hint 2
* You will benefit from a chart with all the html entities so you know which ones are the right ones to put.
### Hint 3
* You should separate the string and work with each character to convert the right ones and then join everything back up.
---
## Solutions
Solution 1 (Click to Show/Hide)
```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
Solution 2 (Click to Show/Hide)
```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
Solution 3 (Click to Show/Hide)
```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()