# Hellohub exercices
### Instructions
- Use TypeScript
- As you know every code solution can be found in google, please do your best to complete the exercices by yourself, however if you are stuck, don't worry, find a solution in internet that will help you to resolve the problem, but don't forget to mention that during our code review.
- ENJOY 😉 !
### 1. Array
```js
/**
* Given an array composed by the 5 first letter of alphabet ["a", "b", "c", "d", "e"]
* return a new array that returns the letters in a capitalized form
* the function should return ["A", "B" ....].
*/
function upperCaseLetters(lowerCaseLetters): string[]
```
### 2. Algo
- Write a function to find the longest common prefix string amongst an array of strings.
- If there is no common prefix, return an empty string "".
Example 1:
```
Input: strs = ["flower","flow","flag"]
Output: "fl"
```
Example 2:
```
Input: strs = ["dog","racecar","car"]
Output: ""
Explanation: There is no common prefix among the input strings.
```