# Arrays In JavaScript


# In JavaScript, an array is a single variable used to store different elements. It is often used when we want to store a list of elements and access them by a single variable. 

### Why Use Arrays?
If you have a list of items (a list of color names, for example), storing the colors in single variables could look like this:
```
let color1= "Red";
let color2 = "Yellow";
let color3 = "DarkGreen";
let color4 = "Violet";
let color5 = "Blue";
``` 
### Creating an Array

```
const colors= ["Red", "Yellow", "DarkGreen","Violet","Blue"];
``` 
### Changing an Array Element
```
const colors[0] = "Brown";
```
***Result:***
```
["Brown", "Yellow", "DarkGreen","Violet","Blue"];
```
> Note: Array indexes start with 0.
> 
> [0] is the first element. [1] is the second element.

### Access the Full Array
```
const colors= ["Red", "Yellow", "DarkGreen","Violet","Blue"];

for(let element of colors){
    console.log(element);
}
```
***Output:***
```
Red
Yellow
DarkGreen
Violet
Blue
```
### The length Property
The length property of an array returns the number of array elements.

```
const colors= ["Red", "Yellow", "DarkGreen","Violet","Blue"];

const lenthOfColors = colors.length;
console.log(lenthOfColors);
``` 
***Result:***

```
5
``` 
### Output the First Element of the color Array
```
const colors= ["Red", "Yellow", "DarkGreen","Violet","Blue"];

console.log(colors[0]);
```
***Result:***

```
Red
``` 
### Adding Array Element

```
const colors= ["Red", "Yellow", "DarkGreen","Violet","Blue"];
colors.push("Gray");
console.log(colors);
``` 
***Result:***

```
[ 'Red', 'Yellow', 'DarkGreen', 'Violet', 'Blue', 'Gray' ]
``` 
### Remove Last Element of an Array

```
const colors= ["Red", "Yellow", "DarkGreen","Violet","Blue"];
colors.pop();
console.log(colors);
``` 
***Result:***
The last element "Blue" is removed from the color array. Now color array does not have "Blue" element.

```
[ 'Red', 'Yellow', 'DarkGreen', 'Violet' ]
``` 
### Merging (Concatenating) Arrays

```
const colors= ["Red", "Yellow", "DarkGreen","Violet","Blue"];
const Newcolors= ["BlueViolet", "Purple", "LightGreen","Lime","DarkBlue"];

const extraColors = colors.concat(Newcolors);

console.log(extraColors);
``` 
***Output:***

```
[
  'Red',       'Yellow',
  'DarkGreen', 'Violet',
  'Blue',      'BlueViolet',
  'Purple',    'LightGreen',
  'Lime',      'DarkBlue'
]
``` 
### JavaScript Array forEach()

The forEach() method calls a function for each element in an array. The forEach() method is not executed for empty elements.

```
const colors= ["Red", "Yellow", "DarkGreen","Violet","Blue"];

colors.forEach(color => console.log(color));
``` 
***Output:***

```
Red
Yellow
DarkGreen
Violet
Blue
``` 
**The forEach() method calls a function for each element in an array.**

**The forEach() method is not executed for empty elements.**