# JavaScript functions travel first class

Functions in JavaScript are first-class citizens of the language just like Objects.

Functions enjoy all the same privileges (in fact more) as do the Objects in JavaScript.

Privileges such as 

### 1. Functions can be created via a literal notation.

```
var obj = {a : 2, b: 2}; // object literal

var add = function(a, b) { // function literal
	return a + b;
};
```

### 2. Functions can be assigned to variables, array entries and object properties.

```

var add = function(a, b) { // function assigned to a variable
	return a + b;
};

var arr = [];
arr[0] = add; // function assigned to array entry at index 0

var obj = {};
obj.addMethod = add; // function assigned to Object obj as a addMethod property

```

### 3. Functions can be passed as arguments to other functions.

```
var values = [34, 56, 12, 11 , 5, 123];

var descendingComparator = function(value1, value2) {
	return value2 - value1;
}
values.sort(descendingComparator); // function descendingComparator passed as argument

console.log(values); // this should print [123, 56, 34, 12, 11, 5] 
```

### 4. Functions can be returned as values from other functions

```
function multiplier(x) {
	return function(y) { return x * y;};
}

var doubleIt = multiplier(2);
console.log(doubleIt(2)); // prints 4

var tripleIt = multiplier(3);
console.log(tripleIt(3)); // prints 9
```

### 5. Functions can also have their own properties and these properties can be added or removed dynamically

```
function myFunc() {}

myFunc.prop1 = 'prop1';

console.log(myFunc.prop1); // prints prop1
```

In addition to all of the above, Functions also have a special superpower in that they can be _invoked_