Filtering arrays with filter(), sort, reverse

jsArrayReverse.js

/*
Transpose the order of the elements in the array
reverse() mutates the array and returns a reference to it.
*/

var array = [1,2,3,4,5,6,7];
var newArray = [];

newArray = array.reverse();

jsFilterAndSort.js

/*
Pass sort a callback with a comparison function. The following example sorts the array from
largest to smallest.
sort() will mutate the array and return a reference to it.
*/

var array = [1, 12, 21, 2];

array.sort(function(a, b) {
  return b - a;                 // Use return a - b to sort from smallest to largest.
});

jsFilterArray.js

/* 
The following filters out any value greater than/equal to 5.
In other words, if the return condition (val <= 5) is true, the value is added to the newArray array.
filter() does not mutate the array.
*/

var oldArray = [1,2,3,4,5,6,7,8,9,10];
var newArray = [];

newArray = oldArray.filter(function(val) {
  return val <= 5;
});