PHP Tutorials - Herong's Tutorial Examples - v5.17, by Herong Yang
Data Literals Examples for Integer, String and Other Data Types
This section provides a tutorial example on how to use data literals for various data types: TRUE, FALSE, and NULL; decimal, octal and hexadecimal numbers; floating point number format; single quoted, double quoted, and heredoc strings.
To help us understand better on how to use data literals for various data types, I wrote the following tutorial sample script:
<?php /* DataLiteralSamples.php #- Copyright 2003 (c) HerongYang.com. All Rights Reserved. */ print "\n\n Boolean data literals: "; $isGood = TRUE; $isBad = false; print "\n TRUE: ".$isGood; print "\n false: ".$isBad; print "\n\n Integer data literals in decimal form: "; $leapYearDays = 366; $supercoolWater = -42; $earthRadius = 6371; print "\n 366: ".$leapYearDays; print "\n -42: ".$supercoolWater; print "\n 6371: ".$earthRadius; print "\n\n Integer data literals in octal form: "; $leapYearDays = 0556; $supercoolWater = -052; $earthRadius = 014343; print "\n 0556: ".$leapYearDays; print "\n -052: ".$supercoolWater; print "\n 014343: ".$earthRadius; print "\n\n Integer data literals in hexadecimal form: "; $leapYearDays = 0x16E; $supercoolWater = -0x2A; $earthRadius = 0x18E3; print "\n 0x16E: ".$leapYearDays; print "\n -0x2A: ".$supercoolWater; print "\n 0x18E3: ".$earthRadius; print "\n\n Float data literals in hexadecimal form: "; $pi = 3.14159; $lightSpeed = 3e8; $gdpGrowth = -1.25e-2; print "\n 3.14159: ".$pi; print "\n 3e8: ".$lightSpeed; print "\n 2.7322e1: ".$gdpGrowth; print "\n\n String data literals in single quoted form: "; $title = 'Today\'s Special:'; $headers = 'Item\tPrice\tUnit'; $apples = 'Apples\t3.49\tkg'; $eggs = 'Eggs\t1.99\tdozen'; print "\n ".$title; print "\n ".$headers; print "\n ".$apples; print "\n ".$eggs; print "\n\n String data literals in double quoted form: "; $title = "Today\'s Special:"; $headers = "Item\tPrice\tUnit"; $apples = "Apples\t3.49\t\x6B\x67"; $price = 1.99; $eggs = "Eggs\t$price\tdoz\145\156"; print "\n ".$title; print "\n ".$headers; print "\n ".$apples; print "\n ".$eggs; print "\n\n String data literals in heredoc form: "; $todaySpecial = <<<EOS Today's Special: Item Price Unit Apples 3.49 kg Eggs 1.99 dozen EOS; print "\n".$todaySpecial; print "\n\n Null data literals: "; $nothing = NULL; $void = null; print "\n NULL: ".$nothing; print "\n null: ".$void; ?>
If you run this sample script, you should get:
herong> \php\php DataLiteralSamples.php Boolean data literals: TRUE: 1 false: Integer data literals in decimal form: 366: 366 -42: -42 6371: 6371 Integer data literals in octal form: 0556: 366 -052: -42 014343: 6371 Integer data literals in hexadecimal form: 0x16E: 366 -0x2A: -42 0x18E3: 6371 Float data literals in hexadecimal form: 3.14159: 3.14159 3e8: 300000000 2.7322e1: -0.0125 String data literals in single quoted form: Today's Special: Item\tPrice\tUnit Apples\t3.49\tkg Eggs\t1.99\tdozen String data literals in double quoted form: Today\'s Special: Item Price Unit Apples 3.49 kg Eggs 1.99 dozen String data literals in heredoc form: Today's Special: Item Price Unit Apples 3.49 kg Eggs 1.99 dozen Null data literals: NULL: 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