# Presentation of the main ES6 features

## Spread Operator

It allows an iterable to expand items in it.

```javascript
array = [1, 2];
appended = [3,4];

all = [...aray, ...appended]
console.log(all)
```

This can be usefull in some situations like this one :

```javascript
array = [1, 2, 3, 4];
console.log(Math.min(...array));
```

instead of the old syntax

```javascript
array = [1, 2, 3, 4];
console.log(Math.min.apply(null, array));
```

## Rest Operator

Represent infinite number or args in an array

```javascript
const sum = (...numbers) => {
    return numbers.reduce((previous, current) => {
        return previous + current;
    });
};
```

## Arrow Function

Function can now be written like this

```javascript
const f = (a, b) => a + b;
console.log(f(1,2));
```

instead of

```javascript
function f(a, b) {
    return a + b;
}
console.log(f(1,2));
```

## Default parameters

With arrow syntax !

```javascript
const f = (a = 10) => console.log(a);
f();
f(1);
```

## Destructuring (arrays and objects)

With arrays

```javascript
const array = [1, 2];
const [a, b] = array;
console.log(a, b)
```

or objects

```javascript
const person = { name: "Jesus", age: "33" };
const { name, age } = person;
console.log(name, age);
```