---
# System prepended metadata

title: Hellohub exercices

---

# 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.
```