Data Literals Examples for Integer, String and Other Data Types

<< PHP Data Types and Data Literals

<< PHP Tutorials - Herong's Tutorial Examples

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) 2005 by Dr. Herong Yang. http://www.herongyang.com/
*/

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: 2005.

Sections in This Chapter

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