# Array methods in Javascript

Bonjour tech-nerd !! <br>
In this blog we'll see about some important must known array methods of javascript.
```
Content
1. Array in general
2. Why methods?
3. forEach()
4. Map()
5. Filter()
6. Reduce()
```
Lets get started 🎉
<hr>
## 1. Array
> Array is a collection/list of data stored in a single variable.

Syntax1: `const arrayName = new Array(item1, item2, item3...); ` <br>
Syntax2: `const arrayName = [item1, item2, item3...]; `

**Array Creation & accessing:**

```javascript
const games = ["Football","Cricket", "Snake&Ladders","Ludo"];
//indexing
console.log(games[1]);  //Books
//using for-loop
for(let i=0;i<games.length; i++){
     console.log(i);
}
//Output:
Football
Cricket
Snake&Ladders
Ludo
```
## 2. Why methods?
Methods are predefinded function to access and modify array elements efficiently. There more 
[array methods](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array#instance_methods) avialable. But we only see some.

## 3. forEach()
>Basically for and forEach() both does the same this i.e to iterate through the array.
The only difference is that `forEach()` uses **callback function** where `for` **loops through the  array** sequentially.
```javascript
const hobbie = ["Photography","Books", "Music"];
hobbie.forEach((item)=>{
     console.log(item);
});
```
- Output:
```sh
Photography
Books
Music```

### For vs forEach()

|      For     | forEach() |
| --------- | --------- |
| **Supports** break statement  | Do **not supports** break statement|
| Ordinary loop itertion | Irerates by callback function |
| Faster performance | Slower performance |

At the end of the day, both does the similar operation. It only depends on your personal preference.

## 4. Map()
> **map()** method works same as the forEach but as the callback function hits every element it **creates a new array** with upcomming the result. 
>
```javascript
const nums = [1,2,3,4,5];
var result=nums.map((item)=>{
     return item*2;
});
console.log(result);
```
- Output:
`[2,4,6,8,10]`

## 5. Filter()
> **filter()** method creates a new array from a given array which satisfy a given condition.
```javascript
const nums = [1,2,3,4,5,6,7,8,9,10];
var result=nums.filter((item)=>{
     return (item%2==0); // returns even number
});
console.log(result);
```
- Output:
`[2,4,6,8,10]`

## 6. Reduce()
> As the name insists **reduce()** method reduce the array to a **single value** as per the reducer function. It takes two required param `total and current value`.
```javascript
// sumof all elements
const nums = [1,2,3,4,5,6,7,8,9,10];
const sum = nums.reduce((total, curr) =>{  //params can be named anything.
     return (total + curr);
}); 
console.log(sum);
```
- Output:
`55`

> Alright nerds! Thats it for now, hope it helped. Thanks for reading. Stay tuned!! See you👋.