- PHP Tutorial
- PHP Syntax
- PHP Variables
- PHP Data Types
- PHP Constants
- PHP Operators
- PHP if elseif else statements
- PHP Switch Statement
- Arrays in PHP
- Loops in PHP
- Strings in PHP
- GET and POST in PHP
- Functions in PHP
- Cookies in PHP
- Sessions in PHP
- Include and Require in PHP
- File Opening and Reading in PHP
- File Creation and Writing in PHP
- Form Validation in PHP
- Date and Time Functions in PHP
- Validation and Sanitizing Data Via PHP Filters
- Introduction to Object Oriented Programming in PHP
- Parameterized Constructors in PHP
- Inheritance in Object Oriented PHP
- Abstract Class in PHP
- Math Functions in PHP
- Error and Exception Handling in PHP
- Reading XML data in PHP
- Reading XML Nodes/Attributes Values in PHP
- XML DOM Parser
- Sorting Arrays in PHP
- Commonly Used Array Functions in PHP
- Commonly Used String Functions in PHP
- Access Modifiers in PHP
- Variable Examination Functions in PHP
- File Upload in PHP
- PHP and AJAX
- PHP Frameworks
- Connecting PHP to MySQL
- Create Database in MySQL via PHP Script
- Drop Database in MySQL via PHP Script
- Selecting Mysql Database via PHP Script
- Create Table in MySQL via PHP Script
- Drop Table in MySQL
- Inserting Data in MySQL Table via PHP Script
- Selecting MySQL Table Data via PHP Script
- Where Clause in MySQL
- Update MySQL Table data via PHP Script
- Deleting Data From MySQL Table via PHP Script
- Sorting MySQL table data via PHP Script
- LIKE Query in MySQL
- Select Unique Data via Distinct In MySQL
- IN Operator in MySQL
- Using BETWEEN operator in MySQL
- AND/OR Operators In MySQL
- Selecting Limited records via LIMIT in MySQL
- Max and Min Functions in MySQL
- SUM and AVG Functions in MySQL
- Using COUNT Function in MySQL
- UCASE and LCASE Functions in MySQL
- GROUP BY and HAVING Clauses in MySQL
- INSERT INTO SELECT in MySQL
- DEFAULT Statement in MySQL
- Implementing Check on Table Columns
- INNER JOIN in MySQL
- LEFT JOIN in MySQL
- RIGHT JOIN In MySQL
- Implementing FULL Join in MySQL
PHP Data Types
In PHP, a variable holds different values of various data types. Following data types are supported by PHP:
- Integers
- Strings
- Doubles
- Booleans
- Arrays
- Objects
- Null
- Resources
Integers
They are a non-decimal numbers and can be negative, zero and positive values. The range of integers is -2,147,483,648 to 2,147,483,647. Integers can be in three different formats: Hexadecimal (Base 16), Decimal (Base 10) and Octal (Base 8).
In the given below example, variables $KH_Number1 and $KH_Number2 are assigned an integer value. You can know the datatype of variable using var_dump function of PHP.
<?php
$KH_Number1 = 3120;
var_dump($KH_Number1);
$KH_Number2 = 451 + 98421;
var_dump($KH_Number2);
?>Download the code Run the code
Strings
They are sequences of the characters. String can be defined using single quote and double quote. Single quote will consider the string as it is, whereas, double quote can parse the variable and replace its value.
<?php
$KH_Name = "John";
$KH_DisaplyName1 = 'My name $KH_Name is not displayed here';
$KH_DisaplyName2 = "My name is $KH_Name";
echo $KH_DisaplyName1 . "<br>"; // Output: My name $KH_Name is not displayed here
echo $KH_DisaplyName2 ; // Output: My name is John
?>Download the code Run the code
Doubles
They are numbers with decimal places like 461.45.
<?php
$KH_Double = 945.12;
var_dump ($KH_Double);
?>Download the code Run the code
Booleans
They have likely two states either true or false. Booleans are frequently used in conditional testing with if statement.
<?php
$KH_Knowphp = true;
if ($KH_Knowphp)
echo "I know PHP script";
else
echo "I don't know PHP script";
?>Download the code Run the code
null
It is a special data type which contains only one value: null. The variable of null data types means that variable is not assigned with any value. It is often used with isset() function.
<?php
$KH_Name = null;
if (!isset($KH_Name))
echo "Variable does not contain value";
else
echo "Variable has the value of $KH_Name";
?>Download the code Run the code