Daniel Dumas » PHP http://danieldumas.com Just another WordPress weblog Wed, 04 Aug 2010 11:02:56 +0000 http://wordpress.org/?v=2.9.2 en hourly 1 PHP Operators: The === Operator http://danieldumas.com/php-operators-the-triple-equals-operator.php http://danieldumas.com/php-operators-the-triple-equals-operator.php#comments Thu, 05 Mar 2009 02:17:12 +0000 Daniel http://danieldumas.com/?p=700 PHP’s === Operator enables you to compare or test variables for both equality and type. Refer below for example.

<?php
//define variables..
$str = '9';
$int = 9;

//Returns true since both variable contains the same value..
$res = ($str==$int);

//Returns false since the two variables are not of the same type..
$res = ($str===$int);
?>
]]> http://danieldumas.com/php-operators-the-triple-equals-operator.php/feed 9 PHP Operators : Using Comparison Operators http://danieldumas.com/php-operators-using-comparison-operators.php http://danieldumas.com/php-operators-using-comparison-operators.php#comments Tue, 03 Mar 2009 17:28:06 +0000 Daniel http://danieldumas.com/?p=686 To compare php variables to determine whether they are the same or different.. you can use PHP Comparison Operators. See below for a list of examples..

I. Define the Variables

<?php
$num1 = 9;
$num2 = 9;
$num3 = 22;
?>

A. The Less Than Operator

<?php
//Returns true if variable in the left side is less than the right..
$res = ($num1 < $num3);
//returns true..
?>

B. The Greater Than Operator

<?php
//Returns true if the variable in left side is greater that the right..
$res = ($num3 > $num1);
//returns true..
?>

C. The Less Than or Equal-to Operator

<?php
//returns true if variable on left is less than or equal to right..
$res = ($num3 <= $num1);
//returns false
?>

D. The Greater Than or Equal-to Operator

<?php
//returns true if variable on left is greater than or equal to right..
$res = ($num3 >= $num2);
//returns true..
?>

E. The Equality Operator

<?php
//returns true if both variables are equal to each other
$res = ($num1 == $num2);
//returns true..
?>

F. The Not Equal-to Operator

<?php
//returns true if the variable on left is not equal to right
$res = ($num1 != $num2);
//returns false..
?>

G. The Inequality Operator

<?php
//returns true if the variable on left is not equal to right..
$res = ($num1 <> $num2);
//returns false..
?>
]]> http://danieldumas.com/php-operators-using-comparison-operators.php/feed 6 PHP Operators: Using String Concatenation Operator http://danieldumas.com/php-operators-using-string-concatenation-operators.php http://danieldumas.com/php-operators-using-string-concatenation-operators.php#comments Sun, 18 Jan 2009 23:03:36 +0000 Daniel http://danieldumas.com/?p=682 You can concatenate or add strings together using the PHP string concatenation operator represented by the period sign ( . ). refer to the examples below.

<?php
// intialize variables
$username = "daniel";
$domain = "danieldumas.com";

// the variable string $username and $domain can be combine using the concatenation operator
$email_address = $username . '@'. $domain;

//the variable $email_address now contains the value "daniel@danieldumas.com"

?>

You can also concatenate simultaneously. .

<?php

$name = "dan";

//add and assign values to the string $name..

$name .= "iel";

//the variable $name now contains "daniel"

?>
]]> http://danieldumas.com/php-operators-using-string-concatenation-operators.php/feed 6 PHP Operators : Using Arithmetic Operators http://danieldumas.com/php-operators-using-arithmetic-operators.php http://danieldumas.com/php-operators-using-arithmetic-operators.php#comments Sun, 04 Jan 2009 12:37:38 +0000 Daniel http://danieldumas.com/?p=673 Using Arithmetic Operators in PHP you can perform mathematical operations on PHP variables. refer to the example below.

Using PHP Arithmetic Operator

//define variables
<?php

$num1 = 50;
$num2 = 30;

//Addition
$sum = $num1 + $num2;

//Subtraction
$difference = $num1 - $num2;

//Multiplication
$product = $num1*$num2;

//Division
$quotient = $num1 / $num2;

//Modulus
$remainder = $num1 % $num2;

?>

you may also use the shorthand using the PHP Assignment Operator and Arithmetic Operator together.

PHP Assignment Operator and Arithmetic Operator Together

//define variables

< ?php

$num1 = 50;
$num2 = 30;

//Addition
$num1 = $num1+ $num2;
//Shorthand for this is..
$num1+=$num2;

//Subtraction
$num1 = $num1 - $num2;
//Shorthand for this is..
$num1-=$num2;

//Multiplication
$num1 = $num1 * $num2;
//Shorthand for this is..
$num1 *=$num2;

//Division
$num1 = $num1 / $num2;
//Shorthand for this is..
$num1 /=$num2;

//Modulus
$num1= $num1 % $num2;
//Shorthand for this is..
$num1%=$num2;

?>
]]> http://danieldumas.com/php-operators-using-arithmetic-operators.php/feed 0 PHP Operators http://danieldumas.com/php-operators.php http://danieldumas.com/php-operators.php#comments Wed, 31 Dec 2008 14:17:32 +0000 Daniel http://danieldumas.com/?p=670 PHP Operators are very important, if PHP variables is the building blocks of PHP programming PHP Operators is the tool that lets you do something useful with variables. php comes with many useful operators such as Assignment Operator, Arithmetic Operator, String Operator, Comparison Operator and Logical Operator.

Below is a list of PHP Operators and its function

PHP OPERATORS
= Assignment
+ Addition
- Subtraction
* Multiplication
/ Division
% Modulus
. String Concatenation
== is equal to
=== is equal to and of the same type
<> or != Not equal to
<
 Less than
> Greater Than
<= Less than or Equal to
>= Greater than or Equal to
&& Logical AND
|| Logical OR
xor Logical XOR
! Logical NOT
++ Increment or Addition by 1
– Decrement or Subtraction by 1
]]> http://danieldumas.com/php-operators.php/feed 6 Detecting the data type of a PHP variable http://danieldumas.com/detecting-the-data-type-php-variable.php http://danieldumas.com/detecting-the-data-type-php-variable.php#comments Fri, 28 Nov 2008 16:47:51 +0000 Daniel http://danieldumas.com/?p=663 Detecting the datatype of a specific PHP variable can be done by using PHP gettype() function. refer below for example.

<?php

//define variables
$on = true;
$age = 20;
$name = "daniel";
$price = 99.99;

//Returns Boolean
echo gettype($on);

//Returns String
echo gettype($name);

//Returns Integer
echo gettype($age);

//Returns Double
echo gettype($price);

?>


You can also use other PHP functions to determine the datatypes of a variable

FUNCTION NAME
is_bool() Checks if a variable is a BOOLEAN
is_string() Checks if a variable is a STRING
is_numeric() Checks if a variable is a NUMERIC STRING
is_int() Checks if a variable is an INTEGER
is_array() Checks if a variable is an ARRAY
is_object() Checks if a variable is an OBJECT
is_null() Checks if a variable is NULL
is_float() Checks if a variable is a FLOAT
]]> http://danieldumas.com/detecting-the-data-type-php-variable.php/feed 5 PHP and MySQL Basics: Saving form input in PHP variables http://danieldumas.com/saving-form-input-values-to-php-variables.php http://danieldumas.com/saving-form-input-values-to-php-variables.php#comments Mon, 10 Nov 2008 20:09:26 +0000 Daniel http://danieldumas.com/?p=630 form can add interactivity to your site, it enables you to get information or comments from your visitors. saving a value from a form input to a php variable is very easy. refer to the example below.

Example 1: Processing forms in the same php file

Copy and Paste the code below to your text editor and save it as form.php, then run it on your localhost

<html>
<head>
<title>Saving Form Input in PHP Variables</title>
</head>
<body>

<form method="post">
Enter message : <input type="text" name="msg">
<input type="submit" value="Print Msg">

<?php
// stores the form data into a php variable
$msg = $_POST['msg'];
//Prints the data retrieve from the form
echo "You said: <b>$msg</b>";
?>

</body>
</html>

Example 2: Processing Form using external php file

Copy and Save the code below to your text editor and save it as form2.php

<html>
<head>
<title>Saving Form Input in PHP Variables</title>
</head>
<body>

<form action="msghandler.php" method="post">
Enter message : <input type="text" name="msg">
<input type="submit" value="Print Msg">

</body>
</html>

Copy and Save the code below to your text editor and save it as msghandler.php in the same folder where form2.php is located, this is the php script that will process the form2.php above

<?php
// stores the form data into a php variable
$msg = $_POST['msg'];
//Prints the data retrieve from the form
echo "You said: <b>$msg</b>";
?>

You Should Get this output in your browser. .

Before clicking the print button

Saving Form Input Into a PHP Variable

After Clicking the print button

Saving Form Input Into a PHP Variable

]]> http://danieldumas.com/saving-form-input-values-to-php-variables.php/feed 2 Fix wordpress fatal error allowed memory size exhausted http://danieldumas.com/wordpress-fatal-error-allowed-memory-size-exhausted.php http://danieldumas.com/wordpress-fatal-error-allowed-memory-size-exhausted.php#comments Fri, 24 Oct 2008 02:24:30 +0000 Daniel http://danieldumas.com/?p=506

Fatal error: Allowed memory size of …… bytes exhausted (tried to allocate …. bytes) in home/of/some/thing/fishy.php :)

Wordpress Fatal Error allowed memory size exhaustedI experienced this weird Wordpress or rather PHP error last night when trying to view my blog when i got home, at first i thought that there was a technical problem at my server so i waited, then i waited and waited and waited again for almost 7 hours then i cant wait no more i want to blogggg… so i contact my hosting provider and they told me that there is nothing wrong with the server nahhh WTF! i told to my self. . :) but i cant figure out the problem at first. .then i figure out that i can access other part of my site. .so i said to myself.. hmm maybe its because of the plugin that i last installed so again i waited and let the night past but the error was still there when i woke up. .did you know what did i do? haha call me dumb coz i dont know what to do so i decided to delete my blog files and install wordpress again but ofcourse i backed up my database so i can restore. . but the problem is still there nahh WTF again i said to my self. . haha :) until i found a bit of code that can save my life sana haha :o hhyeahh: . . PHP Memory Allocation Error was the real problem it is an error returned by php when it used up the default memory limit, it occurs when PHP is handling or processing a large amount of data or records more that its default memory allocation. I found to 3 ways to Fix this problem

1st: Increase the memory limit of an individual PHP file

ini_set(”memory_limit”,”16M”);

Put this code at the top of every PHP file that errors are showing, you can expand the memory by changing the 16M to a other value if your still getting errors,. you can set it to 16M, 18M etc..

2nd: edit your PHP.INI file – this option will apply to all the php files in your site

search your php.ini file and find memory_limit: put values like at the top for example

memory_limit: 16M

3rd: use .htaccess to expand the memory allocation – this option will apply to all the php files in your site

php_value memory_limit 32000000

Copy and paste the code above to your .htaccess file

Thats it! the errors are gone :D

]]> http://danieldumas.com/wordpress-fatal-error-allowed-memory-size-exhausted.php/feed 8 PHP and MySQL Basics: Assigning and Using Variables http://danieldumas.com/assigning-php-variables.php http://danieldumas.com/assigning-php-variables.php#comments Sun, 05 Oct 2008 23:34:30 +0000 Daniel http://danieldumas.com/?p=284 Assigning a value to PHP variable is very easy, you can use the assignment operator ( = ) to store values into a php variable. refer below for example.

<html>
<head>
<title>Assigning Values to PHP Variable</title>
</head>
<body>
<?php
//this is how you assign a value to a php variable
$age = 20;
//To use the variable $age, simply call its name and PHP will substitute its value at runtime.
//this is how you use a php variable
echo "I am now $age years old";
?>
</body>
</html>

copy and paste the code above to your text editor and save it as variable.php then run it on your localhost.

you should get this output..

assigning values to php variables

]]> http://danieldumas.com/assigning-php-variables.php/feed 4 PHP and MySQL Basics: Variables http://danieldumas.com/php-variables.php http://danieldumas.com/php-variables.php#comments Sun, 05 Oct 2008 22:37:53 +0000 Daniel http://danieldumas.com/?p=280 Variables are the building blocks of any programming language. in PHP variables are very important, it used to store numeric or non-numeric datas. PHP supports different types of variable types (Booleans, Integers, Floating point numbers, Strings, Arrays, Objects, resources and nulls.

PHP VARIABLE NAMING RULES:

  1. PHP variables starts with a $ sign : example. $daniel
  2. $ sign is followed by a letter or an underscore. thus $123 is not a valid PHP variable.
  3. it can contain letters, numbers, underscores or even dashes.
  4. no spaces
  5. PHP variables are CASE-SENSITIVE thus $daniel and $DANIEL are completely different variable.

EXAMPLES OF VALID PHP VARIABLES

$dan
$Daniel
$myVariable – Camel case style
$my_variable
$my-variable
$item1
$_note
$__noteBook

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