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 (c) 2015, 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:

 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:

Last update: 2015.

Table of Contents

 About This Book

 Introduction and Installation of PHP 7.0

 PHP Script File Syntax

PHP Data Types and Data Literals

 Data Types Supported in PHP

 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

 Arrays - Ordered Maps

 Configuring and Sending out Emails

 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

 Introduction of Class and Object

 Integrating PHP with Apache Web Server

 Outdated Tutorials

 References

 PDF Printing Version