Retrieving an Element of an Array

From Rosetta Code
Revision as of 22:01, 23 January 2007 by Adonis (talk | contribs) (Properly ordering the languages)
Task
Retrieving an Element of an Array
You are encouraged to solve this task according to the task description, using any language you may know.

In this task, the goal is to retrieve an element of an array.

x86 assembly

Assembler: nasm

mov esi, array_offset
mov ebx, 2
mov eax, [esi+ebx*4]

Template:Array operation

C

 int array_index(int array[], int index) {
   return array[index];
 }

C#

 int getArrayValue( int values[], int index ) {
   return values[index];
 }
 

C++

 template <class T>
 T array_index(T *array, int index) {
   return array[index];
 }

Common Lisp

  (defun array-value (array index)
    (aref array index))

mIRC

Interpeter: mIRC Script Editor Library: mArray Snippet

 alias readmyarray { echo -a $array_read(MyArray, 2, 3) }

Perl

Interpreter: Perl 5.8.8

$elem = $array[0];

PHP

$array = array('php', 'has', 'arrays');
// First element 
$elem  = $array[0];

Python

Interpreter: Python 2.5

The item is an element in a list at a given index

 item = aList[index]

or

To use a list like a stack be it FIFO/LIFO

 aList.pop()  # Pop last item in a list
 aList.pop(0) # Pop first item in a list

Note: When using the pop() method, the element is removed from the list.

Ruby

 ary = ['Ruby','rules','big','time']
 #the first element
 element = ary[0]
 #or
 element = ary.first
 # => element = 'Ruby'
 #the last element
 element = ary[-1]
 #or
 element = ary.last
 # => element = 'time'
 #retrieving different values at once
 elements = ary.values_at(0,2,3)
 # => elements = ['Ruby','big','time']
 #select the first element of length 3
 element = ary.find{|el|el.length==3}
 # => element = "big"