1. Arithmetic operation program using PHP

<?php
$str=" Arithmetic operation";
$a=4;
$b=5;
$c=$a+$b;
echo "Sum=", $c;
$c=$a-$b;
echo "<br>Sub=", $c;
$c=$a*$b;
echo "<br>Mul=", $c;
$c=$a/$b;
echo "<br>Div=", $c;
?>

2. PHP program to print person name and age.

<?php
$name="John";
$age=20;
echo "Person name=", $name;
echo "<br>Age=", $age;
?>

3. PHP Program to SWAP 2 Numbers

<?php
$a=4;
$b=5;
echo "A: before swap=", $a;
echo "<br>B: before swap=", $b;
$c=$a;
$a=$b;
$b=$c;
echo "<br>A: After swap=", $a;
echo "<br>B: After swap=", $b;
?>

4.  PHP Program to test whether the number is +ve or -ve.

<?php
$a=-10;
if ($a>0)
{
echo "Number is positive";
}
else
{
echo "Number is negative";
}
?>

5. PHP program to test whether the person is Eligible to vote or not.

<?php
$age=19;
$name="John";
if ($age>=18)
{
echo $name, " is eligible for vote";
}
else
{
echo $name, " is NOT eligible for vote";
}
?>