Day 1 – PHP Overview

 

PHP test

To test php environment whether it is installed correctly or php settings.

<?php phpinfo(); ?>

It will show php all configurations.

Output

PHP variable

Variable syntax

• Start with $ sign
• Name the variable
  • no space
  • no capital letter
  • variable names are case sensitive
  • no symbol
• variable types
  • string: ‘Dhaka’;
  • integer: 123456;
    • no quotation
  • floating number: 1.23456;
    • no quotation
  • boolean true false
    • 0 = fales
    • 1 = true
  • array();
    • array(‘one’, ‘two’);

    • array(
               array(
                  'one',
                  'two'
               )
      );

Example of print variables

Integer

<?php 
$roll = 6;
?>
<h1>My roll number is <?php echo $roll; ?>.</h1>

Output

String (way one)

<?php
$city = 'Dhaka and Rajshahi';
?>

<h1>Two most beautiful cities are <?php echo $city; ?>.</h1>

Output

String (way two)

• using php concat
• ‘ . . ‘

 <?php
$city = 'Dhaka and Rajshahi';
echo '<h1>Two most beautiful cities are '.$city.'.</h1>'
?>

Output

PHP if

• <?php if() : ?>
  <?php endif; ?>,

<?php
$beautiful = 'Rajshahi';
?>

<?php if($beautiful == 'Rajshahi') : ?>
<h1>The most beautiful city is $beautiful.</h1>
<?php endif; ?>

Output

PHP if else – false value

<?php
$beautiful = 'Dhaka';
?>

<?php if($beautiful == 'Rajshahi') : ?>

<h1>The most beautiful city is $beautiful.</h1>

<?php else : ?>

<h1>We don't know</h1>

<?php endif; ?>

Output

PHP if else – true value

<?php 
$beautiful = 'Rajshahi'; 
?> 
<?php 
if($beautiful == 'Rajshahi') : ?> 
<h1>The most beautiful city is $beautiful.</h1> 
<?php else : ?> 
<h1>We don't know</h1> 
<?php endif; ?>

Output

PHP if else – all in one php tag

• <?php if() {
  echo '';
  } else {
  echo '';
  }

<?php

$beautiful = 'Rajshahi';

if($beautiful == 'Rajshahi') {

echo '<h1>The most beautiful city is '.$beautiful.'.</h1>';

} else {

echo '<h1>We don\'t know</h1>';

}

?>

Output

PHP array()

• array data point starts with 0 then 1, 2, 3 …..

<?php
$cities = array('Dhaka', 'Rajshahi', 'Khulna', 'Barisal');
echo '<h1>The second city is '.$cities[1].'.</h1>';
?>

Output

PHP array() with if else

<?php
$cities = array('Dhaka', 'Rajshahi', 'Khulna', 'Barisal');


if($cities[3] == 'Rajshahi') {
echo '<h1>The forth city is '.$cities[3].'.</h1>';
} else {
echo '<h1>We don\'t know.</h1>';
}
?>

Output

PHP equal variable

<?php
$city1 = 'Dhaka';
$city2 = 'Dhaka';


if($city1 == $city2) {
echo '<h1>The name of my city is '.$city1.'.</h1>';
} else {
echo '<h1>We don\'t know.</h1>';
}
?>

Output