This document serves as a lecture on basic PHP concepts, covering variables, operators, arrays, and loops with examples. It explains single and multiline comments, various types of operators (arithmetic, assignment, comparison), and how to work with arrays in PHP. Additionally, it details different looping constructs like for, while, do-while, and foreach with practical coding examples.

1. Web
Development(PHP)
Lecture 2
Variables, Operators, Arrays, Loops

2. Basic Syntax (Single Line Comments)
<?php
//This is Single Line Comment
echo "<h1> Hello </h1>";
print "Class";
?>

3. Basic Syntax (MultiLine Comments)
<?php
/*This is Other Comment
This is multiline comment
This is last line of comment*/
echo "<h1> Hello </h1>";
print "Class";
?>

4. Operators
• Concatenation Operator (.)
• Arithmetic Operators(+,-,/,*,%)
• Assignment Operators(=)
• Increment/Decrement Operators(++,--)
• Comparison Operator(==,===,<,>,<=,>=)

5. Plus Operator
<?php
$x=5;
$y=6;
$z=$x+$y;
echo "The Result =" .$z;?>

6. Minus Operator
<?php
$x=5;
$y=6;
$z=$x-$y;
echo "The Result =" .$z;?>

7. Multiplication Operator
<?php
$x=5;
$y=6;
$z=$x*$y;
echo "The Result =" .$z;?>

8. Division Operator
<?php
$x=5;
$y=6;
$z=$x/$y;
echo "The Result =" .$z;?>

9. Modulus Operator
<?php
$x=5;
$y=6;
$z=$x%$y;
echo "The Result =" .$z;
?>

10. Increment/Decrement Operators
<?php
$x=100;
$y=15;
$x++;
echo "<br/> X Incremented Values = ".$x;
$y--;
echo "<br/> X Decremented Values = ".$y;
?>

11. Comparison Operators (==,===)
• <?php
• $x=5;
• $y="Hello";
• $z="hello";
• if ($z===$y) {
• echo "Both Variables are Equals";
• }else
• {
• echo "Both Variables are Not Equals";
• }
• ?>

12. Array in PHP
• Array is the linear collection or group of multiple amount of data
• In php there are only dynamic array not static
• Array define in php:
$variablename=array();

13. Array in PHP
<?php
$myarr=array();
$myarr[0]=1;
$myarr['hi']="HELLO";
echo $myarr[0]."<br/>";
echo $myarr['hi'];
?>

14. Array in PHP
<?php
$myarr=array(0=>1,'hi'=>"HELLO");
echo $myarr[0]."<br/>";
echo $myarr['hi'];
?>

15. Array in PHP
<?php
$myarr=array();
$myarr[0]=1;
$myarr[]="HELLO";
$myarr[]=50;
echo "<pre>";
print_r($myarr);
echo "</pre>";
<?php
$myarr=array();
$myarr[0]=array(12,13);
//It means it is two dimentional array
//Like
//$myarr[0][0]=12;
//$myarr[0][1]=13;
echo "<pre>";
print_r($myarr);
echo "</pre>";

16. Loops in PHP
For Loop
While loop
Do while loop
Foreach loop

17. FOR Loop in PHP
Example:1
<?php
for ($i=0; $i <=9 ; $i++) {
echo "Square of ".$i." =
".($i*$i)."<br>";
}
?>
Example:2
<?php
$farray=array(1,2,3,4,5,6,7,8,9,0);
for ($i=0; $i <=9 ; $i++) {
echo $farray[$i]."<br>";
}
?>

18. While/do While Loop
<?php
$farray=array(1,2,3,4,5,6,7,8,9,0);
$result=count($farray);
$i=0;
while ($i <= $result) {
echo $farray[$i]." , ";
$i++;
}
?>
<?php
$farray=array(1,2,3,4,5,6,7,8,9,0);
$result=count($farray);
$i=0;
do {
echo $farray[$i]." , ";
$i++;
}while ($i > $result)
?>

19. foreach(Loop)
<?php
$farray=array("num1"=>1,"num2"=
>2,3,4,5);
$result=count($farray);
$i=0;
foreach($farray as $a) {
echo $a." ";
}
?>
<?php
$farray=array("num1"=>1,"num2"=
>2,3,4,5);
$result=count($farray);
$i=0;
foreach($farray as $a=>$b) {
echo $a." => ".$b."</br>";
}
?>

20. Let’s Practice