PHP Sample Problem: This application loads a csv datafile from the command line, manipulates the data and provides information based on the ID provided.

class.shapes.php

<?php
/**
* 
* @author "Will Nielsen"
* website: http://willnielsen.com
* Date: December 13, 2013
*/


class Shapes {

    /**
     * The document root
     */
    private $_docRoot = null;

    /**
     * data file
     */
    private $_dataFile;

    /**
     * The header row from the csv
     */
     protected $_headerRow;

    /**
     * Associative Array containing data found in the
     * data.csv file.
     */
    protected $_shapes = array();

    public function __construct($datafile) {
        // sets the doc root for this file        
        $this -> _setDocroot();
        // sets the absolute path for the datafile
        $this -> _dataFile = $this -> _docRoot . '/' . $datafile;
        // returns an array of shapes found in the datafile (csv)
        $this -> _shapes = $this -> _loadCsv();
    }

    private function _setDocroot() {
        $this -> _docRoot = rtrim(dirname(__FILE__), '\\/');
    }

    private function _loadCsv() {

        // Shape Type: array key containing either rectangle or circle
        define('SHAPE_ID', 0);
        define('SHAPE_TYPE', 1);
        define('SHAPE_RADIUS_OR_WIDTH', 2);
        define('SHAPE_HEIGHT', 3);
        $numlines = count(file($this -> _dataFile));
        $delimiter = ',';
        $data = array();

        if (!file_exists($this -> _dataFile) and !is_readable($this -> _dataFile))
           throw new Exception($this->_datafile . " either does not exist or is not readable.", 1);
           

        if (($handle = fopen($this -> _dataFile, 'r')) !== FALSE) {

            while (($row = fgetcsv($handle, 1000, $delimiter, '"')) !== FALSE) {
                // Check for rectangles
                if (strtolower($row[SHAPE_TYPE]) == 'rectangle') {

                    $data[] = array(
                        'id' => trim($row[SHAPE_ID]), 
                        'type' => trim($row[SHAPE_TYPE]), 
                        'width' => trim($row[SHAPE_RADIUS_OR_WIDTH]), 
                        'height' => trim($row[SHAPE_HEIGHT]), 
                        'area' => $row[SHAPE_RADIUS_OR_WIDTH] * $row[SHAPE_HEIGHT]);

                }
                // otherwise assume circle
                else {
                    $data[] = array(
                        'id' => trim($row[SHAPE_ID]), 
                        'type' => trim($row[SHAPE_TYPE]), 
                        'radius' => trim($row[SHAPE_RADIUS_OR_WIDTH]), 
                        'area' => round(M_PI * pow($row[SHAPE_RADIUS_OR_WIDTH], 2),2));
                }
            }
            fclose($handle);
            
            // remove the header row from the array
            $this->_headerRow = array_shift($data);
            return $data;
        }
    }

    protected function _getShapeType($id) {
        $shape = $this -> getShapeById($id);
        return $shape['type'];
    }
    public function getShapeArrayKeyById($id)
    {
        foreach ($this -> _shapes as $key => $shape) {
            if ($shape['id'] == $id) {
                return $key;
            }
        }
        return FALSE;
    }
    public function getShapeById($id) {
        foreach ($this -> _shapes as $shape) {
            if ($shape['id'] == $id) {
                return $shape;
            }
        }
        return FALSE;
    }

    public function getShapes() {
        return $this -> _shapes;
    }
    
    public function sortShapesByArea($direction = ASC)
    {
        $tmp = array();
        
        foreach($this->_shapes as &$multi)
        {
            $tmp[] = &$multi['area'];
        }
        array_multisort($tmp,$this->_shapes);
    }
        
    public function listShapes($tableCaption = null)
    {
        $doubleLine = '===============================================================================================' . PHP_EOL;
        $line       = '-----------------------------------------------------------------------------------------------' . PHP_EOL;
        $pad        = "\t";
        $out = '';
        
        if(!is_null($tableCaption))
        {
            $out .= $doubleLine;
            $out .= ' ' . $tableCaption . PHP_EOL;
            $out .= $line;
        }
        else 
        {
            $out .= $doubleLine;
        }
        
        $out .= "{$pad}ID{$pad}|";
        $out .= "{$pad}Type{$pad}{$pad}|";
        $out .= " Radius or Width |";
        $out .= " [Height]    |";
        $out .= " Area ";
        $out .= PHP_EOL;
        $out .= $doubleLine;
                
        foreach($this->_shapes as $array)
        {
            $out .= $pad . $array['id'] . $pad . '|';
            $out .= $pad . $array['type'];
            $out .= ($array['type'] == 'rectangle') ? $pad : $pad . $pad;
            $out .= '|';
            ($array['type'] == 'rectangle') ? 
                $out .= $pad . $array['width'] . $pad . '  |' :
                $out .= $pad . $array['radius'] . $pad . '  |';
            ($array['type'] == 'rectangle') ? 
                $out .= $pad . $array['height'] . $pad . '|' :
                $out .= $pad . 'n/a' . $pad . '|';
                $out .= ' ' . $array['area'];
            $out .= PHP_EOL;
            
            $out .= $line;
        }
        $out .= $doubleLine;
        
        return $out;
    }
}

data.csv

ID, type, radius or width/height
2,circle,5,
33,rectangle,23,90
5,rectangle,32,44
23,circle,8,
29,rectangle,22,34
66,circle,2,
35,rectangle,54,63
87,circle,111,
86,rectangle,44,98
90,circle,234,
867,circle,66,
5309,rectangle,22,12
16,circle,9,
17,rectangle,88,23
56,rectangle,78,46
52,circle,18,
421,rectangle,6,37
99,circle,17,
90210,circle,45,
42,rectangle,100,54

main.php

<?php
/**
* 
* @author "Will Nielsen"
* website: http://willnielsen.com
* Date: December 13, 2013
*/


require_once ('class.shapes.php');

$cmd = array_shift($argv);
$datafile = $argv[0];
$shapeId = $argv[1];

$obj = new Shapes($datafile);

/* Read file and a create an object array of shapes */
//var_dump($obj->getShapes());
echo PHP_EOL;
$obj->getShapes();

/* Get the array index of the shape with ID that was passed in and write to screen */
echo 'The array index of shape (id=' . $shapeId . ') is [' . $obj->getShapeArrayKeyById($shapeId) . ']' . PHP_EOL;
echo PHP_EOL;

/* Sort the shapes by area and write the results to the screen */
$obj->sortShapesByArea();
echo $obj->listShapes('Shapes Sorted by Area (ASC)');
echo PHP_EOL;

/* Get the new array index of the shape with ID that was passed in and write to screen */
echo 'The new array index of shape (id=' . $shapeId . ') is [' . $obj->getShapeArrayKeyById($shapeId) . ']' . PHP_EOL;
echo PHP_EOL;