Basics of PHP

minimal_php.php

########
# ARRAYS
<?php
$marr = array('helga', 'rollo', 'ivar');
$i = 0;
while($i < 3){
	$j = 0;
	while($j < $i){
		echo "\t";
		$j++;
	}
	echo "[$i] $marr[$i]\n";
	$i++;
}

$marr[3] = 'sigi';
$marr[50] = 'athelwulf';
foreach($marr as $elem){
	echo $elem . "\n";
}

?>


############
# CONSTANTS
<?php
define('PI', 3.14);
echo "The value of pi is " . PI . "\n";
?>


############
# Dictionary
<?php
$mdict = array('one' => 1, 'two' => 2, 3 => 'three');

foreach ($mdict as $k => $v){
	echo "$k : $v\n";
}

?>


##########
# FOR LOOP
<?php
$num = 0;
for($num=1; $num<=20; $num+=1.2){

	echo $num;
	if ($num < 20){
		echo ", ";
	}

}
?>


##########
# FUNCTION
<?php
function add($a, $b){
	return $a + $b;
}

echo "Call Function : " . add(1.6, 3.99999) . "\n";

?>


######################
# HELLO WORLD
<?php
$x = "hello world";
echo "$x\n";
?>


###########
# IF...ELSE
<?php
define('A', 5);
$a = 5;

if ($a > A){
	echo '$a is greater than A by ' . ($a - A);
} elseif ($a < A){
	echo '$a is lesser than A by ' . (-$a + A);
} else{
	echo '$a and A are equal.';
}


if ($a == A){
	echo "\n" .  'a == A';
}


$b = 5;

if ( ($a > $b) || ($a == A) ){
	echo "\n" . 'a = A or a > b';
}

if ($a == $b){
	echo "\n" . 'a == b';
}

if (! ($a > $b) ){
	echo "\n" . 'a !> b';
}

?>


##############
# PRINT
<?php
echo "cool";
?>


#######################
# Reference to variable
<?php
$x = 2.7;
$ref_to_x = &$x;
echo "ref_to_x : $ref_to_x\n";
$x++;
echo "ref_to_x : $ref_to_x\n";
?>


######################
# Arithmetic shorthand
<?php
$x = 1.2;
$x += 0.1;
echo "[1] updated x : $x\n";
echo "[2] updated x : " . $x += 0.1;
echo "\n";
echo "[3] another x : " . $x++ . "\n";
echo "[4] another x : " . ++$x . "\n";
?>


###################
# String Operations
<?php
$mstr = '  My Special Variable  ';
echo "Len : " . strlen($mstr) . "\n";
echo "ltrim : |" . ltrim("$mstr") . "|\n";
echo "rtrim : |" . rtrim("$mstr") . "|\n";
echo "trim : |" . trim("$mstr") . "|\n";
echo "upper : |" . strtoupper("$mstr") . "|\n";
echo "lower : |" . strtolower("$mstr") . "|\n";

$mstr_to_arr = explode(' ', $mstr);
echo "string to array :\n";
echo "[";
foreach( $mstr_to_arr as $elem){
	echo "$elem ,";
}
echo "]\n";

$arr_to_mstr = implode(' ', $mstr_to_arr);
echo "array to string : $arr_to_mstr\n";

echo "substring \"var\" in mstr : " . substr($arr_to_mstr, 13, 3) . "\n";

echo "string compare : " . strcmp($arr_to_mstr, " " + $mstr) . "\n";

echo "Everything after \"var\" : " . strstr($mstr, "Var") . "|\n";
echo "Everything after \"var\" (case insensitive): " . stristr($mstr, "var") . "|\n";
echo "Location of match \"var\" (case insensitive): " . stripos($mstr, "var") . "\n";

echo "String replace : " . str_replace('Var', 'Rav', $mstr);
?>


###########
# Switch
<?php
$namev = "helgi";

switch($namev){

	case "helga":
		echo "hi helga\n";
		break;

	case "rollo":
		echo "hi rollo\n";
		break;

	case "rickety":
		echo "hi rick\n";
		break;

	default:
		echo "Who the hell are you?\n";

}

?>


##################
# Ternary Operator
<?php
$max_num = (14 > 7)? 14 : 7;
echo $max_num . "\n";
?>


################
# TYPE CASTING
<?php
$x = 8.3;
echo "int(x) : " . (integer)$x . "\n";
?>

#######
# WHILE
<?php
$num = 10;

while($num < 45){
	echo $num . ", ";
	$num++;
}

echo "\n";
?>