Arrays

  • Array elements are zero-based.
  • Arrays are objects.
  • Trailing commas at the end of array literals are ignored.
  • An array literal is a type of object initializer.
Indexed array
var numArray = new Array(1);
numArray[0] = new Array(2);
numArray[0][0] = "red";
numArray[0][1] = "round";
# Array literal
var colors = ["orange", "blue", "green"];
var animals = ["lion", , "zebra"];        # animals[1] is undefined.
var fish = ["bass", , ,];                 # This array contains only 1 element.
Associative array
var assocArray = new Array();
assocArray["apple"] = new Array();
assocArray["apple"]["color"] = "red";
assocArray["apple"]["shape"] = "round";
# Array literal   (JavaScript Object Notation (JSON))
var assocArray = {"lemon":"yellow", "lime":"green"};

Properties


length
  • The number of elements in the array.

Methods


concat
  • Joins two arrays and returns a new array.
var myArray = arr1.concat(arr2);
join
  • Joins all elements of an array into a string.
var myStr = myArray.join(", ");
pop
  • Removes and returns the last element from an array.
push
  • Adds one or more elements to the end of an array and returns the last element added.
reverse
  • Reverses the order of the array elements.
shift
  • Removes and returns the first element from an array.
slice
  • Returns a portion of an array and as a new array.
splice
  • Adds and/or removes elements from an array.
sort
  • Sorts the array elements.
unshift
  • Adds one or more elements to the front of an array and returns the new length of the array.