1. Booleans
Boolean is simple true/false
<?php
$bool1 = true;
$bool2 = false;
echo $bool1;
echo $bool2;
?>

2. <?php
$var1 = 3;
$var2 = “cat”;
echo isset($var1);
echo isset($var2);
echo isset($var3);
?>

3. <?php
unset($var1);
echo isset($var1);
echo isset($var2);
echo isset($var3);
echo empty($var1);
?>

4. Type switching and casting
$var1 = “hello”;
$var2 = 10;
echo gettype($var1);
echo gettype($var2);
settype($var2, “string”);
echo gettype($var2);
$var3 = (int) $var1;
echo gettype($var3);

5. Constants
$width = 90;
define(“width”, 980);
echo width;
width += 1;
echo width;

6. Loops
Initialization;
While (condition)
{
Statement;
Iteration;
}
Example :
$count = 0;
while($count<=10){
echo $count;
$count++; }

7. do while loop
initialization
do
{
Statement;
Iteration;
}
while(condition);

8. Example:
$a=0;
do
{
echo $a;
$a++;
}
while($a<=10);

9. For loop
For(initialization;condition;iteration)
{
Statement;
}
Example:
for($count=0; $count <= 10; $count++)
{
echo $count;
}

10. Break statement
$i = 0;
while( $i < 10)
{
echo $i;
if( $i == 3 )
break;
$i++;
}
echo "loop stop at i = $i";

11. Continue
for($count=0;$count<=10;$count++)
{
if ($count == 5)
{
continue;
}
echo $count." ";
}

12. Pre defined variables:
$_GET to access all the sent information using GET
method.
$_POST to access all the sent information using POST
method
$_COOKIE contains any variables provided to a script
through a cookie
$_SESSION contains any variables that are registered in
a session.

13. <form method=“post” action=“ ”>
First no. <input type=“text” name=“fnum”>
<input type=“submit” name=“submit”>
</form>
<?php
If(isset($_POST[‘submit’]))
{
$fnum=$_POST[‘fnum’];
echo $fnum;
?>