gistfile1.php

<?php
class ArrayTest extends PHPUnit_Framework_TestCase {

	public function testNextAndPrev1(){
		
		$rs = array(1=>1,2=>2,3=>3,4=>4,5=>5);
		$curID = 3;
		
		$prev = null;
		foreach ($rs as $ID => $r){
			if ($ID==$curID) break;
			$prev=$r;
		}
		$next = current($rs);
		
		$this->assertEquals($prev,2);
		$this->assertEquals($next,4);
	}

	public function testNextAndPrev2(){
		
		$rs = array(1=>1,2=>2,3=>3,4=>4,5=>5);
		$curID = 3;
		
		list($prev, $next) = $this->getBackNext2($rs, $curID);
		$this->assertEquals($prev,2);
		$this->assertEquals($next,4);
	}

	public function testNextAndPrev3(){
		
		$rs = array(1=>1,2=>2,3=>3,4=>4,5=>5);
		$curID = 3;
		
		list($prev, $next) = $this->getBackNext3($rs, $curID);
		$this->assertEquals($prev,2);
		$this->assertEquals($next,4);
	}
	
	private function getBackNext2($rs, $curID=null){
		
		$prev = null;
		foreach ($rs as $ID => $r) {
			if ($ID==$curID) break;
			$prev=$r;
		}
		$next = current($rs);
		return array($prev, $next); 
	}
	
	private function getBackNext3(&$rs, $curID=null){
             
		$prev = null;
		foreach ($rs as $ID => $r) {
			if ($ID==$curID) break;
			$prev=$r;
		}
		$next = current($rs);
		return array($prev, $next); 
	}
}