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Article Description: the Array data structure

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Content: use HTML Edit Content <h1 style="text-align: center;">Arrays</h1> <h2>[WHAT]</h2> <ol> <li><strong>] Array stores a number of elements in a specific order. Here are some examples</strong></li> <ol> <li>] pets = ["dog","cat","mouse"]</li> <li>] numbersOdd = [1,3,5,7,9]</li> <li>] datesHolidays2013 =&nbsp; ['2013-01-01','2013-04-21','2013-07-01']</li> <li>] namesHolidays = ['New Years Day','Good Friday', 'Canada Day']&nbsp;</li> </ol> <li><strong>] They are accessed using an integer to specify which element is required (although the elements may be of almost any type).</strong></li> <ol> <li>] var myPet = pets[0], where 0 is the first element in the pets &nbsp;Array</li> </ol> <li><strong>] Typical implementations allocate contiguous memory words for the elements of arrays (but this is not always a necessity).</strong></li> <ol> <li>] how arrays are stored in memory, a sequential block of</li> </ol> <li><strong>] Arrays may be fixed-length or expandable.</strong></li> <ol> <li>]</li> </ol> <li><strong>] single dimensional array</strong></li> <ol> <li>] the array contains a number of items(), all of the same type</li> </ol> <li><strong>] multi-dimensional arrays</strong></li> <ol> <li>]</li> </ol></ol> <h2>[WHY]</h2> <ol> <li><strong>] define ...</strong></li> <ol> <li>]&nbsp;a collection of contiguous elements, may be a fixed size or expandable(dynamic),&nbsp;each element is accessed by its numeric index&nbsp;</li> <li>] a set/collection of related data elements accessed by their index</li> <li>] stores a number of elements in a specific order. They are accessed using an integer (index)&nbsp;to specify which element is required (although the elements may be of almost any type). Typical implementations allocate contiguous memory words for the elements of arrays (but this is not always a necessity). Arrays may be fixed-length or expandable.</li> </ol> <li><strong>] operations on array </strong><ol> <li>] Allocation</li> <li>] Accessing</li> <li>] Redimensioning</li> </ol></li> </ol> <h2>[WHERE]</h2> <ol> <li>]</li> </ol> <h2>[WHEN]</h2> <ol> <li>]</li> </ol> <h2>[EXAMPLE]</h2> <h2>[HOW-TO example code, language = javascript]</h2> <ol> <li><strong>] CREATE / DECLARATION</strong></li> <ol> <li>] var&nbsp;pets = new Array("dog","cat","mouse") || var pets = ["dog","cat","mouse"];</li> </ol> <li><strong>] ACCESS</strong></li> <ol> <li>] return pets[1];&nbsp; // output =&nbsp;cat</li> </ol> <li><strong>] ADD ELEMENT</strong></li> <ol> <li>] pets.push("gerbil"); - adds a new element to the end of the array, returns the new length of the array</li> </ol> <li><strong>] REMOVE ELEMENT</strong></li> <ol> <li>] pets.pop() - removes the last element of the array,</li> </ol> <li><strong>] REPLACE ELEMENT</strong></li> <ol> <li>] pets[0] = "pup";</li> </ol> <li><strong>] MORE Methods and Examples in</strong></li> <ol> <li>] javascript arrays</li> </ol></ol> <h2>[REFERENCE]</h2> <ol> <li>]</li> </ol> <h1 style="text-align: center;">&nbsp;</h1>