PHP Introduction

//1. Print current date
	echo date("F j, Y, g:i a");

//2. Type of variable
	$boolVar = true;
        $intVar = 9;
        $doubVar = 1.23;
        $strVar = 'Coffee';
        $arrVar = array(3, 9, 4, 16);
        $nullVar = null;
        $resourceVar = mysql_connect();
        $objVar = (object) 'Ivan Ivanov';
        echo gettype($boolVar) . "</br>";
        echo gettype($intVar) . "</br>";
        echo gettype($doubVar) . "</br>";
        echo gettype($strVar) . "</br>";
        echo gettype($arrVar) . "</br>";
        echo gettype($nullVar) . "</br>";
        echo gettype($resourceVar) . "</br>";
        echo gettype($objVar);

//3. Rectangle Area
	$a = 5;
        $b = 10;
        $area = $a * $b;
        echo "Rectangle's area is: " . $area;

//4. Triangle Area
	$x1 = 15;
        $y1 = 1;
        $x2 = 25;
        $y2 = 52;
        $x3 = 32;
        $y3 = 13;
        $area = ($x1*($y2-$y3) + $x2*($y3-$y1) + $x3*($y1 - $y2))/2;
        echo "Triangles's area is: " . round(abs($area));

//5. Boolean Variable
	//First version.
        $isFemale = true;
        $answer = ($isFemale) ? 'True' : 'False';
        echo "Am I a female?  -" . $answer . "</br>";
        //Second version.
        if ($isFemale == true) {
            echo "I am a female.";
        }
        else
            echo "I am not a female.";

//6. Quotes in Strings
	$withQuotes = "I asked a girl out and she said - \"I don't know\". Does she mean yes or no?";
        echo "Using quoted string: " . $withQuotes . "</br>";
        $withoutQuotes = <<<EOT
        I asked a girl out and she said - "I don't know". Does she mean yes or no?
EOT;
        echo "Without using quoted string: " . $withoutQuotes;

//7. Type Casting
	$float = 2.4;
        echo "$float is: " . gettype($float) . "</br>";
        settype($float, 'integer');
        echo "$float is: " . gettype($float);

//8. Print Html
	$h = '<h1>Hello World</h1>';
        $p = '<p>I love Software Univerity</p>';
        echo htmlspecialchars($h) . "</br>";
        echo htmlspecialchars($p);

//9. Divide by 2 and 9
	$int = 2;
        if ($int % 2 == 0) {
            if ($int % 9 == 0) {
                echo 'true';
            }
            else
                echo 'false';
        }
        else
            echo 'false';

//10. Third Digit is 7?
	$int = 8143747;
        $result = (integer)$int / 100;
        if ($result % 10 == 7) {
            echo "true";
        }
        else
            echo "false";

//11. Numbers from 1 to n
	$n = 20;
        for ($i = 1; $i <= $n; $i++) {
            echo $i . "</br>";
        }

//12. Fibonacci numbers
	$x = 1;
        $y = 0;
        $n = 10;
        echo "0 ";
        for($i = 2; $i <= $n; $i++) {
            $z = $x + $y;
            echo $z . " ";
            $x = $y;
            $y = $z;
        }