What are the differences between php7 and php5? Comparison between php5 and php7

# /usr/local/php7/bin/php -v
PHP 7.1.5 (cli) (built: May 13 2017 23:36:41) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2017 Zend Technologies

# /usr/bin/php -v
PHP 5.6.30 (cli) (built: Jan 19 2017 22:31:39) 
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies

$arr = array();
for ($i = 0; $i < 500000; $i++) {
        $arr[$i] = $i;
}

$tmp = array();
foreach ($arr as $i) {
    if ($i % 2 == 0) {
        $is_exists = array_key_exists($i, $arr);
        if ($is_exists) {
           array_push($tmp, $i);
        }
    }
}

time /usr/bin/php test.php 
real    0m0.301s
user    0m0.239s
sys     0m0.050s
--------------------------
time /usr/bin/php test.php
real    0m0.310s
user    0m0.241s
sys     0m0.054s
--------------------------
time /usr/bin/php test.php
real    0m0.289s
user    0m0.238s
sys     0m0.050s

time /usr/local/php7/bin/php test.php

real    0m0.087s
user    0m0.063s
sys     0m0.024s
-------------------------------------
time /usr/local/php7/bin/php test.php

real    0m0.106s
user    0m0.073s
sys     0m0.033s
--------------------------------------
time /usr/local/php7/bin/php test.php

real    0m0.083s
user    0m0.061s
sys     0m0.022s

Table: test_user
Create Table: CREATE TABLE `test_user` (
  `uid` int(11) NOT NULL AUTO_INCREMENT,
  `name` char(100) NOT NULL DEFAULT '',
  PRIMARY KEY (`uid`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8

insert into test_user (uid,name) values (1,"dada");
MariaDB [test]> select * from test_user;
+-----+------+
| uid | name |
+-----+------+
|   1 | dada |
+-----+------+

/usr/bin/php -m|grep pdo
pdo_mysql
pdo_sqlite

/usr/local/php7/bin/php -m|grep pdo
pdo_mysql
pdo_sqlite

$host = "yourHost";
$user = "yourUser";
$pass = "yourPass";
$db   = "test";
$port = 3306;

try
{
  $dbh = new PDO("mysql:host=$host;dbname=$db", $user, $pass);
  echo "Connected<p>";
}
catch (Exception $e)
{
  echo "Unable to connect: " . $e->getMessage() ."<p>";
}

$sql = "select  SQL_NO_CACHE * from test_user;";
$tmp = array();
for ($i=1; $i<=500000; $i++) {
  $ret = $dbh->query($sql);  
  foreach ($ret as $row) {
    $tmp[&#39;id&#39;]   = $row[&#39;id&#39;];
    $tmp[&#39;name&#39;] = $row[&#39;name&#39;];
  }
}

time /usr/bin/php test_db.php
real    0m48.396s
user    0m11.149s  
sys     0m3.998s

real    0m51.447s
user    0m11.800s
sys     0m4.395s

real    0m51.517s
user    0m11.733s
sys     0m4.439s

real    0m47.900s
user    0m9.875s
sys     0m4.130s

real    0m46.977s
user    0m9.760s
sys     0m3.983s

real    0m50.010s
user    0m10.268s
sys     0m4.307s

time /usr/bin/php ./public/index.php
real    0m0.036s
user    0m0.026s
sys     0m0.010s

real    0m0.038s
user    0m0.026s
sys     0m0.012s

real    0m0.041s
user    0m0.032s
sys     0m0.009s

time /usr/local/php7/bin/php ./public/index.php
real    0m0.027s
user    0m0.021s
sys     0m0.005s

real    0m0.027s
user    0m0.018s
sys     0m0.009s

real    0m0.025s
user    0m0.023s
sys     0m0.002s

<?php
namespace app\index\controller;

class Index
{
    public function index()
    {
       $arr = array();
       for ($i = 0; $i < 500000; $i++) {
           $arr[$i] = $i;
       }

       $tmp = array();
       foreach ($arr as $i) {
           if ($i % 2 == 0) {
               $is_exists = array_key_exists($i, $arr);
               if ($is_exists) {
                   array_push($tmp, $i);
               }
          }
      }
    }
}

time /usr/bin/php ./public/index.php
real    0m0.538s
user    0m0.463s
sys     0m0.072s

real    0m0.454s
user    0m0.386s
sys     0m0.065s

real    0m0.387s
user    0m0.331s
sys     0m0.055s

time /usr/local/php7/bin/php ./public/index.php
real    0m0.150s
user    0m0.123s
sys     0m0.024s

real    0m0.137s
user    0m0.105s
sys     0m0.031s

real    0m0.123s
user    0m0.096s
sys     0m0.026s

time /usr/bin/php ./public/index.php

real    0m0.104s
user    0m0.081s
sys     0m0.022s

real    0m0.148s
user    0m0.122s
sys     0m0.025s

real    0m0.122s
user    0m0.100s
sys     0m0.021s

time /usr/local/php7/bin/php ./public/index.php

real    0m0.079s
user    0m0.064s
sys     0m0.015s

real    0m0.081s
user    0m0.067s
sys     0m0.014s

real    0m0.067s
user    0m0.054s
sys     0m0.013s

Route::get('/', 'UserController@index');

public function index()
{
      $arr = array();
       for ($i = 0; $i < 500000; $i++) {
           $arr[$i] = $i;
       }

       $tmp = array();
       foreach ($arr as $i) {
           if ($i % 2 == 0) {
               $is_exists = array_key_exists($i, $arr);
               if ($is_exists) {
                   array_push($tmp, $i);
               }
          }
      }
}

time /usr/bin/php ./public/index.php
real    0m0.510s
user    0m0.377s
sys     0m0.079s

real    0m0.627s
user    0m0.447s
sys     0m0.091s

real    0m0.519s
user    0m0.436s
sys     0m0.079s

time /usr/local/php7/bin/php ./public/index.php

real    0m0.201s
user    0m0.167s
sys     0m0.032s

real    0m0.216s
user    0m0.174s
sys     0m0.040s

real    0m0.169s
user    0m0.134s
sys     0m0.034s