<?php

include 'inc/config.php';

# замер времени
function timeMeasure()
{
    list( $msec, $sec ) = explode( chr(32), microtime() );
    return $sec + $msec;
}

# вывод результатов
function timeMeasureEnd( $label )
{
    echo '<p>result ['.$label.'] = '.round( timeMeasure() - constant( $label ), 4 ).'</p>';
}

# генерируем массив
define( 'GENERATE_ARRAY', timeMeasure() );
$ar = array();
for( $i = 0; $i < 100000; ++ $i )
{
    $ar[] = 1;
}
timeMeasureEnd( 'GENERATE_ARRAY' );

# используем указатели
define( 'FOREACH_WITH_POINTER', timeMeasure() );
foreach( $ar as &$value )
{
    ++ $value;
}
timeMeasureEnd( 'FOREACH_WITH_POINTER' );

# используем ключи массива
define( 'FOREACH_WITHOUT_POINTER', timeMeasure() );
foreach( $ar as $key => $value )
{
    $ar[ $key ] = $value + 1;
}
timeMeasureEnd( 'FOREACH_WITHOUT_POINTER' );

# работаем с другим массивом
define( 'FOREACH_WITH_REPLACE', timeMeasure() );
foreach( $ar as $value )
{
    $new_ar[] = $value + 1;
}
$ar = $new_ar;
timeMeasureEnd( 'FOREACH_WITH_REPLACE' );

# используем array_map
define( 'ARRAY_MAP', timeMeasure() );
function test( $value ){ return $value + 1; };
$ar = array_map( 'test', $ar );
timeMeasureEnd( 'ARRAY_MAP' );

?>

result [GENERATE_ARRAY] = 0.0376
result [FOREACH_WITH_POINTER] = 0.0099
result [FOREACH_WITHOUT_POINTER] = 0.0576
result [FOREACH_WITH_REPLACE] = 0.0509
result [ARRAY_MAP] = 0.0867