## Algorithm

Problem Name: 344. Reverse String

Problem URL: https://leetcode.com/problems/reverse-string/

Level: Easy

Details:

Write a function that reverses a string. The input string is given as an array of characters `s`.

You must do this by modifying the input array in-place with `O(1)` extra memory.

Example 1:

```Input: s = ["h","e","l","l","o"]
Output: ["o","l","l","e","h"]
```

Example 2:

```Input: s = ["H","a","n","n","a","h"]
Output: ["h","a","n","n","a","H"]
```

Constraints:

Algorithm:

We can solve this Reverse String problem in several ways.

Method 1: Use javascript `reverse()` method to reverse any string.

``array.reverse();``

Method 2: Using `forEach` or `for` loop to solve the problem.

We can start the loop from end to start.

``````const reversed = [];
for(let i = s.length - 1; i >= 0; i--) {
reversed.push(s[i]);
}

s.forEach((ch, i) => {
s[i] = reversed[i];
});``````

## Code Examples

### #1 Code Example with Javascript Programming

```Code - Javascript Programming```

``````
var reverseString = function(s) {
return s.reverse();
};
``````
Copy The Code &

Input

cmd
["h","e","l","l","o"]

Output

cmd
["o","l","l","e","h"]

### #2 Using For Loop to solve Reverse problem in Javascript [Not tested]

```Code - Javascript Programming```

``````
var reverseString = function(s) {
const reversed = [];
for(let i = s.length - 1; i >= 0; i--) {
reversed.push(s[i]);
}

s.forEach((ch, i) => {
s[i] = reversed[i];
});
};
``````
Copy The Code &

Input

cmd
["H","a","n","n","a","h"]

Output

cmd
["h","a","n","n","a","H"]

## Demonstration

We'll just use string reverse() method of javascript.

Leetcode - 344. Reverse String Solution in Javascript Leetcode