PHP Tutorials - Herong's Tutorial Examples - v5.17, by Herong Yang
Data Literals Supported in PHP
This section describes data literals to specify values for different data types: reserved key words; decimal, octal and hexadecimal numbers; floating point number format; single quoted, double quoted, and heredoc strings.
Data literals are ways to provide values for different data types in PHP source code. PHP data literals rules are summarized below:
1. boolean data literals: Data literals for boolean data type are two reserved key words: true and false. Note that true and false are case in-sensitive - TRUE and FALSE are also valid boolean literals.
2. integer data literals: Data literals for integer data type have 3 forms:
3. float data literals: Data literals for float data type are numeric values represented in signs and decimal digits with a decimal point and or exponential part. For example: 3.14159, 3e8, -1.25e-2, ...
4. string data literals: Data literals for string data type have 3 forms:
5. array data literals: There are no data literals for array data type. Arrays are created by using the array constructor, array() function, or the array element notation, $arrayName[$key].
6. object data literals: There are no data literals for object data type. Objects are created by class constructors.
7. resource data literals: There are no data literals for resource data type. Resources are created by using PHP built-in functions.
8. null data literal: Data literal for null data type is 1 reserved key words: null. Note that null is case in-sensitive - NULL is the same as null.
Table of Contents
Introduction and Installation of PHP
►PHP Data Types and Data Literals
►Data Literals Supported in PHP
Data Literals Examples for Integer, String and Other Data Types
Overflow of Integer and Float Values
Variables, References, and Constants
Expressions, Operations and Type Conversions
Conditional Statements - "if" and "switch"
Loop Statements - "while", "for", and "do ... while"
Function Declaration, Arguments, and Return Values
Interface with Operating System
Introduction of Class and Object
Integrating PHP with Apache Web Server
Retrieving Information from HTTP Requests
Creating and Managing Sessions in PHP Scripts
Sending and Receiving Cookies in PHP Scripts
Controlling HTTP Response Header Lines in PHP Scripts
MySQL Server Connection and Access Functions
Functions to Manage Directories, Files and Images
SOAP Extension Function and Calling Web Services
SOAP Server Functions and Examples
Localization Overview of Web Applications
Using Non-ASCII Characters in HTML Documents
Using Non-ASCII Characters as PHP Script String Literals
Receiving Non-ASCII Characters from Input Forms
"mbstring" Extension and Non-ASCII Encoding Management
Managing Non-ASCII Character Strings with MySQL Servers
Parsing and Managing HTML Documents
Configuring and Sending Out Emails
Managing PHP Engine and Modules on macOS