CHAPTER 7
Introduction to PHP5 Part II
อ.ยืนยง กันทะเนตร
คณะเทคโนโลยีสารสนเทศและการสื่อสาร
มหาวิทยาลัยพะเยา
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Content
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PHP 5 if...else...elseif Statements
PHP 5 switch Statement
PHP 5 while Loops
PHP 5 for Loops
PHP 5 Functions
PHP 5 Arrays
PHP 5 Sorting Arrays
PHP 5 Global Variables - Superglobals
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Content
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PHP 5 Form Handling
PHP 5 Form Validation
PHP 5 Forms - Required Fields
PHP 5 Forms - Validate E-mail and URL
PHP 5 Complete Form Example
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PHP 5 if...else...elseif Statements
PHP - The if Statement
PHP - The if...else Statement
<?php
$t = 15;
<?php
$t = 15;
if ($t < 20) {
echo "Have a good day!";
}
?>
if ($t < 20) {
echo "Have a good day!";
}else{
echo "Have a good night!";
}
?>
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PHP 5 if...else...elseif Statements (cont.)
PHP - The if...elseif....else Statement
<?php
$t = 15;
if ($t < 10) {
echo "Have a good morning!";
} elseif ($t < 20) {
echo "Have a good day!";
} else {
echo "Have a good night!";
}
?>
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PHP 5 switch Statement
The PHP switch Statement
<?php
$favcolor = "red";
switch ($favcolor) {
case "red":
echo "Your favorite color is red!";
break;
case "blue":
echo "Your favorite color is blue!";
break;
default:
echo "Your favorite color is neither red, blue, or green!";
}
?>
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PHP 5 while Loops
The PHP while Loop
The PHP do...while Loop
<?php
$x = 1;
<?php
$x = 1;
while($x <= 5) {
echo "The number is: $x <br>";
$x++;
}
?>
do {
echo "The number is: $x <br>";
$x++;
} while ($x <= 5);
?>
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PHP 5 for Loops
The PHP for Loop
<?php
for ($x = 0; $x <= 10; $x++) {
echo "The number is: $x <br>";
}
?>
The PHP foreach Loop
<?php
$colors = array("red", "green", "blue", "yellow");
foreach ($colors as $value) {
echo "$value <br>";
}
?>
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PHP 5 Functions
Create a User Defined Function in PHP
Syntax
function functionName() {
code to be executed;
}
Example
<?php
function writeMsg() {
echo "Hello world!";
}
writeMsg(); // call the function
?>
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PHP 5 Functions (cont.)
PHP Function Arguments
Example
<?php
function familyName($fname) {
echo "$fname br>";
}
familyName("Jani");
familyName("Hege"); //output Jani Hege
?>
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PHP 5 Functions (cont.)
PHP Default Argument Value
Example
<?php
function setHeight($minheight = 50) {
echo "The height is : $minheight <br>";
}
setHeight(350);
setHeight(); // will use the default value of 50
setHeight(135);
setHeight(80);
?>
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PHP 5 Functions (cont.)
PHP Functions - Returning values
Example
<?php
function sum($x, $y) {
$z = $x + $y;
return $z;
}
echo "5 + 10 = " . sum(5, 10) . "<br>";
echo "7 + 13 = " . sum(7, 13) . "<br>";
echo "2 + 4 = " . sum(2, 4);
?>
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PHP 5 Arrays
What is an Array?
• An array is a special variable, which can hold more than one
value at a time.
$cars1 = "Volvo";
$cars2 = "BMW";
$cars3 = "Toyota";
However, what if you want to loop through the cars and find a
specific one? And what if you had not 3 cars, but 300?
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PHP 5 Arrays (cont.)
Create an Array in PHP
array();
Example
$cars = array("Volvo", "BMW", "Toyota");
or the index can be assigned manually:
$cars[0] = "Volvo";
$cars[1] = "BMW";
$cars[2] = "Toyota";
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PHP 5 Arrays (cont.)
Get The Length of an Array - The count() Function
count();
Example
<?php
$cars = array("Volvo", "BMW", "Toyota");
echo count($cars);
?> //output 3
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PHP 5 Arrays (cont.)
Loop Through an Indexed Array
Example
<?php
$cars = array("Volvo", "BMW", "Toyota");
$arrlength = count($cars);
for($x = 0; $x < $arrlength; $x++) {
echo $cars[$x];
echo "<br>";
}
?>
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PHP 5 Arrays (cont.)
PHP Associative Arrays
Example
<?php
$age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43");
echo "Peter is " . $age['Peter'] . " years old.";
?>
Loop Through an Associative Array
Example
<?php
$age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43");
foreach($age as $x => $x_value) {
echo "Key=" . $x . ", Value=" . $x_value;
echo "<br>";
} ?>
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PHP 5 Sorting Arrays
PHP - Sort Functions For Arrays
In this chapter, we will go through the following PHP array sort
functions:
• sort() - sort arrays in ascending order
• rsort() - sort arrays in descending order
• asort() - sort associative arrays in ascending order, according
to the value
• ksort() - sort associative arrays in ascending order, according
to the key
• arsort() - sort associative arrays in descending order,
according to the value
• krsort() - sort associative arrays in descending order,
according to the key
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PHP 5 Sorting Arrays (cont.)
Sort Array in Ascending Order - sort()
<?php
$cars = array("Volvo", "BMW", "Toyota");
sort($cars);
?>
Sort Array in Descending Order - rsort()
<?php
$cars = array("Volvo", "BMW", "Toyota");
rsort($cars);
?>
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PHP 5 Sorting Arrays (cont.)
Sort Array (Ascending Order), According to Value - asort()
<?php
$age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43");
asort($age);
?>
Sort Array (Ascending Order), According to Key - ksort()
<?php
$age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43");
ksort($age);
?>
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PHP 5 Sorting Arrays (cont.)
Sort Array (Descending Order), According to Value - arsort()
<?php
$age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43");
arsort($age);
?>
Sort Array (Descending Order), According to Key - krsort()
<?php
$age = array("Peter"=>"35", "Ben"=>"37", "Joe"=>"43");
krsort($age);
?>
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PHP 5 Global Variables - Superglobals
PHP Global Variables - Superglobals
Several predefined variables in PHP are "superglobals", which means
that they are always accessible, regardless of scope - and you can access
them from any function, class or file without having to do anything special.
The PHP superglobal variables are:
• $GLOBALS
• $_SERVER
• $_REQUEST
• $_POST
• $_GET
• $_FILES
• $_ENV
• $_COOKIE
• $_SESSION
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PHP 5 Global Variables - Superglobals (cont.)
PHP $_POST
<html>
<body>
<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>">
Name: <input type="text" name="fname">
<input type="submit">
</form>
<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$name = $_POST['fname'];
if (empty($name)) {
echo "Name is empty";
} else {
echo $name;
}
}?>
</body>
</html>
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PHP 5 Global Variables - Superglobals (cont.)
PHP $_GET //test_get.html
<html>
<body>
<a href="test_get.php?subject=PHP&web=W3schools.com">Test $GET</a>
</body>
</html>
PHP $_GET //test_get.php
<html>
<body>
<?php
echo "Study " . $_GET['subject'] . " at " . $_GET['web'];
?>
</body>
</html>
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PHP 5 Form Handling
The PHP superglobals $_GET and $_POST are used to collect form-data.
PHP - A Simple HTML Form $_GET
PHP - A Simple HTML Form
<html>
<body>
<html>
<body>
<form action="welcome_get.php" method=“get">
Name: <input type="text" name="name"><br>
E-mail: <input type="text" name="email"><br>
<input type="submit">
</form>
Welcome
<?php echo $_GET["name"]; ?><br>
Your email address is:
<?php echo $_GET["email"]; ?>
</body>
</html>
</body>
</html>
// output
Welcome name
Your email address is name@example.com
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PHP 5 Form Handling
PHP - A Simple HTML Form $_POST
PHP - A Simple HTML Form
<html>
<body>
<html>
<body>
<form action="welcome_post.php"
method=“post">
Name: <input type="text" name="name"><br>
E-mail: <input type="text" name="email"><br>
<input type="submit">
</form>
Welcome
<?php echo $_POST["name"]; ?><br>
Your email address is:
<?php echo $_POST["email"]; ?>
</body>
</html>
</body>
</html>
// output
Welcome name
Your email address is name@example.com
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PHP 5 Form Validation
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PHP 5 Form Validation (cont.)
// formValidate.php
<?php
$name = $email = $gender = $comment = $website = "";
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$name = test_input($_POST["name"]);
$email = test_input($_POST["email"]);
$website = test_input($_POST["website"]);
$comment = test_input($_POST["comment"]);
$gender = test_input($_POST["gender"]);
}
function test_input($data) {
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
?>
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PHP 5 Form Validation (cont.)
// formValidate.php
<h2>PHP Form Validation Example</h2>
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
Name: <input type="text" name="name">
<br><br>
E-mail: <input type="text" name="email">
<br><br>
Website: <input type="text" name="website">
<br><br>
Comment: <textarea name="comment" rows="5" cols="40"></textarea>
<br><br>
Gender:
<input type="radio" name="gender" value="female">Female
<input type="radio" name="gender" value="male">Male
<br><br>
<input type="submit" name="submit" value="Submit">
</form>
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PHP 5 Form Validation (cont.)
// formValidate.php
<?php
echo "<h2>Your Input:</h2>";
echo $name;
echo "<br>";
echo $email;
echo "<br>";
echo $website;
echo "<br>";
echo $comment;
echo "<br>";
echo $gender;
?>
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PHP 5 Forms - Required Fields
// formValidate.php
<?php
$nameErr = $emailErr = $genderErr = $websiteErr = "";
$name = $email = $gender = $comment = $website = "";
if ($_SERVER["REQUEST_METHOD"] == "POST") {
if (empty($_POST["name"])) {
$nameErr = "Name is required";
} else {
$name = test_input($_POST["name"]);
}
if (empty($_POST["email"])) {
$emailErr = "Email is required";
} else {
$email = test_input($_POST["email"]);
}
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PHP 5 Forms - Required Fields (cont.)
// formValidate.php
if (empty($_POST["website"])) {
$website = "";
} else {
$website = test_input($_POST["website"]);
}
if (empty($_POST["comment"])) {
$comment = "";
} else {
$comment = test_input($_POST["comment"]);
}
if (empty($_POST["gender"])) {
$genderErr = "Gender is required";
} else {
$gender = test_input($_POST["gender"]);
}
}
?>
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PHP 5 Forms - Required Fields (cont.)
// formValidate.php
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
Name: <input type="text" name="name">
<span class="error">* <?php echo $nameErr;?></span>
<br><br>
E-mail:
<input type="text" name="email">
<span class="error">* <?php echo $emailErr;?></span>
<br><br>
Website:
<input type="text" name="website">
<span class="error"><?php echo $websiteErr;?></span>
<br><br>
<label>Comment: <textarea name="comment" rows="5" cols="40"></textarea>
<br><br>
Gender:
<input type="radio" name="gender" value="female">Female
<input type="radio" name="gender" value="male">Male
<span class="error">* <?php echo $genderErr;?></span>
<br><br>
<input type="submit" name="submit" value="Submit">
</form>
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PHP 5 Forms - Validate E-mail and URL
// formValidate.php
PHP - Validate Name
$name = test_input($_POST["name"]);
if (!preg_match("/^[a-zA-Z ]*$/",$name)) {
$nameErr = "Only letters and white space allowed";
}
// formValidate.php
PHP - Validate E-mail
$email = test_input($_POST["email"]);
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
$emailErr = "Invalid email format";
}
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PHP 5 Forms - Validate E-mail and URL (cont.)
// formValidate.php
PHP - Validate URL
$website = test_input($_POST["website"]);
if (!preg_match("/\b(?:(?:https?|ftp):\/\/|www\.)[-a-z09+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i",$website)) {
$websiteErr = "Invalid URL";
}
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PHP 5 Complete Form Example
// formValidate.php
PHP - Keep The Values in The Form
Name: <input type="text" name="name" value="<?php echo $name;?>">
E-mail: <input type="text" name="email" value="<?php echo $email;?>">
Website: <input type="text" name="website" value="<?php echo $website;?>">
Comment: <textarea name="comment" rows="5" cols="40"><?php echo
$comment;?></textarea>
Gender:
<input type="radio" name="gender"
<?php if (isset($gender) && $gender=="female") echo "checked";?>
value="female">Female
<input type="radio" name="gender"
<?php if (isset($gender) && $gender=="male") echo "checked";?>
value="male">Male
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THE END
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