DOWNLOAD_NOTE_Chapter 3_part1
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FP512 WEB PROGRAMMING 1
CHAPTER 3
PHP BASIC PROGRAM
STRUCTURE
PREPARED BY: PN. NUR SYUHADA BINTI MOHAMAD
Learning Outcomes
1. Apply the basic structure of PHP syntax
and program.
2. Create classes and objects in PHP
environment.
3. Use functions in PHP environment.
4. Use arrays and strings in PHP environment.
5. Create PHP web form.
6. Process web form data.
7. Understand cookies and sessions.
3.1 Apply the basic structure of
PHP syntax and program.
- Identify PHP syntax.
- Write statements and comments.
- Declare variables in PHP.
- Assign different data type of a
variable.
- Use different types of operator on
variables.
- Write constants in the PHP script.
- Use Conditional Statements and Loop in
PHP Environment
PHP Syntax
• PHP script always starts
with <?php and ends with ?>
• Shorthand-support, <? and end with ?>
• The others tags that also can be use: <% %>,
<? ?>,<?= ?>
• Example, index.php:
<html>
<body>
<?php echo "Hello World"; ?>
</body>
</html>
Statement in PHP
• PHP must end with a semicolon ( ; )
• Two basic statements to output
text with PHP:
– echo a language construct that has no return value
and cannot be used in an expression.
– print
behaves like a function with its own return
value (although it is a language construct), can be
used in an expression.
Comment in PHP
• // to make a single-line comment
• /* and */ to make a large comment block
or multi line comment.
<html>
<body>
<?php
//This is a comment
/* This is a
comment
block */
?>
</body>
</html>
PHP Variables
• PHP variables are used to hold values or
expressions.
• Rules for PHP variable names:
– Variables in PHP starts with a $ sign, followed
by the name of the variable
– The variable name must begin with a letter or
the underscore character
– A variable name can only contain alphanumeric
characters and underscores (A-z, 0-9, and _ )
– A variable name should not contain spaces .
– Variable names are case sensitive (y and Y are
two different variables)
• Create a variable containing a string, and a
variable containing a number:
<?php
$txt="Hello World!";
$x=16;
?>
Local Scope Variables
• A variable declared within a PHP function is
local and can only be accessed within that
function
<?php
$a = 5; // global scope
function myTest()
{
echo $a; // local scope
}
myTest();
?>
Global Scope Variables
• Any variable that is defined outside of any
function
• Accessed from any part of the script that is
not inside a function
Output:
<?php
$a = 5; $b = 10;
15
function myTest()
{ global $a, $b;
$b = $a + $b;
}
myTest();
echo $b; $GLOBALS['b'] = $GLOBALS['a'] + $GLOBALS['b'];
?>
Operator
• An operator is a symbol or series of symbols
that, when used in conjunction with values,
perform an action and usually produces a new
value.
• An operand is a value used in conjunction with
an operator. There are usually two or more
operands to one operator.
Arithmetic operators
Operator
Name
Example
Sample Result
+
Addition
10 + 3
13
-
Subtraction
10 – 3
7
/
Division
10 / 3
3.33333333333
*
Multiplication
10 * 3
30
%
Modulus
10 % 3
1
The assignment operator (=)
• Basic assignment operator in PHP is "=".
• Example: The value of "$x = 5" is 5.
Incrementing/Decrementing
Operators
Comparison Operators
• Comparison between two values
Logical Operators
Concatenation operator
• Concatenation operator (.) is used to
put two string values together. For example:
<?php
$txt1=“Hai Amy!";
$txt2=“Have a nice day!";
echo $txt1 . " " . $txt2;
?>
Output:
Hai Amy! Have a nice day!
Constants in PHP
• A constant is an identifier (name) for a
simple value. It’s function returns the value of
constant.
• Syntax: constant(constant)
<?php
//define a constant
define("GREETING",“I love PHP");
echo constant("GREETING");
?>
Output:
I love PHP
Exercises
Q1: Uses of Variable
<?php
echo "Twinkle, Twinkle little star. <br/>";
$twinkle="Twinkle";
$star="star";
echo "$twinkle, $twinkle little $star.<br/>";
$twinkle="Thunder";
$star="elephant";
echo "$twinkle, $twinkle little $star.";
?>
Q1: Answer
Q2: Arithmetic Operators
<?php
$num = 8;
echo "Value is now $num.<br/>";
$num += 2;
echo "Add 2. Value is now $num. <br/>";
$num -= 4;
echo "Subtract 4. Value is now $num. <br/>";
$num *= 5;
echo "Multiply by 5. Value is now $num. <br/>";
$num /= 3;
echo "Divide by 3. Value is now $num. <br/>";
$num++;
echo "Increment value by one. Value is now $num.<br/>";
$num--;
echo "Decrement value by one. Value is now $num.";
?>
Q2: Answer
Value is now 8.
Add 2. Value is now 10.
Subtract 4. Value is now 6.
Multiply by 5. Value is now 30.
Divide by 3. Value is now 10.
Increment value by one. Value is now 11.
Decrement value by one. Value is now 10.
Q3: Arithmetic & Assignment
Operators
<?php
$x=10;
$y=7;
$result=$x+$y;
echo "$x + $y =
$result=$x-$y;
echo "$x - $y =
$result=$x*$y;
echo "$x * $y =
$result=$x/$y;
echo "$x / $y =
$result=$x%$y;
echo "$x % $y =
?>
$result<br />";
$result<br />";
$result<br />";
$result<br />";
$result<br />";
Q3: Answer
10 + 7 = 17
10 - 7 = 3
10 * 7 = 70
10 / 7 = 1.4285714285714
10 % 7 = 3
to be continue…