HINF 6220 Networks and the Web for Health Informatics

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Tutorial 11
HINF 6220 (Networks and the Web for Health
Informatics)
PHP
kharrazi_at_cs.dal.ca http//flame.cs.dal.ca/kharraz
i/
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Review Tutorial 10

• PHP Intro
• PHP Syntax lt?php ?gt
• PHP echo echo 'something'
• PHP Commenting // or / /
• PHP Variables x string, number, array

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Have you downloaded theTutorialApps
from http//www.cs.dal.ca/kharrazi/teaching/hin
f_6220/TutorialApps.zip ?
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TutorialApps.zip
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PHP in a Nutshell

• PHP String Manipulations
• PHP Array Manipulations
• PHP Conditions
• PHP Loops
• PHP Functions
• PHP Cookies
• PHP SSI
• PHP Forms
• PHP/MySQL Integration

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1. PHP String Manipulation

• These functions all manipulate strings in various
  ways. Some more specialized sections can be done
  by regular expressions (like Perl) and URL
  handling commands.
• No external libraries are needed to build this
  extension.
• There is no installation needed to use these
  functions they are part of the PHP core.
• For regular expressions please refer to
  http//ca.php.net/manual/en/ref.regex.phphttp//c
  a.php.net/manual/en/ref.pcre.php

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PHP String Manipulation (ctn.)

• Formatting Strings
• Trimming, Case Changing
• Joining and Splitting Strings
• Comparing Strings
• Match and Replace Substrings
• Regular expression
• please refer to
• http//ca.php.net/manual/en/ref.regex.phphttp//
  ca.php.net/manual/en/ref.pcre.php

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PHP StringFormatting (ctn.)

• Trimming Stripping white space (or other
  characters) from the beginning and/or end of a
  string.
• Usually we use these functions to remove
  additional spaces or characters that users might
  have typed mistakenly in the input forms.
• syntax means that is optional.

trim (string, character list) ltrim (string,
character list) rtrim (string, character
list) chop (string)
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PHP StringFormatting (ctn.)
trim
lt?php text " . ... .email me your email... .
. " // Trim echo "Text "."".text."" ec
ho "ltbrgt" echo "Trim "."".trim(text)."" e
cho "ltbrgt" echo "Trim . and space
"."".trim(text, ". ")."" echo "ltbrgt" echo
"Trim e,m,a,i,l,. and space "."".trim(text,
"email. ")."" ?gt
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PHP StringFormatting (ctn.)
trim
TRIM removes the indicated characters (in
this case e, m, a, i, l, . and space from both
sides of the string variable. TRIM does not
change the variable itself and therefore the
variable will remain intact.
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PHP StringFormatting (ctn.)
ltrim
lt?php text " . ... .email me your email... .
. " // Left Trim echo "Text
"."".text."" echo "ltbrgt" echo "Trim
"."".ltrim(text)."" echo "ltbrgt" echo "Trim
. and space "."".ltrim(text, ". ")."" echo
"ltbrgt" echo "Trim e,m,a,i,l,. and space
"."".ltrim(text, "email. ")."" ?gt
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PHP StringFormatting (ctn.)
ltrim
LTRIM removes the indicated characters (in this
case e, m, a, i, l, . and space from the left
side (beginning) of the string variable.LTRIM
does not change the variable itself and therefore
the variable will remain intact.
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PHP StringFormatting (ctn.)
rtrim
lt?php text " . ... .email me your email... .
. " // Right Trim echo "Text
"."".text."" echo "ltbrgt" echo "Trim
"."".rtrim(text)."" echo "ltbrgt" echo "Trim
. and space "."".rtrim(text, ". ")."" echo
"ltbrgt" echo "Trim e,m,a,i,l,. and space
"."".rtrim(text, "email. ")."" ?gt
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PHP StringFormatting (ctn.)
rtrim
RTRIM removes the indicated characters (in this
case e, m, a, i, l, . and space from the right
side (end) of the string variable.RTRIM does not
change the variable itself and therefore the
variable will remain intact.
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PHP StringFormatting (ctn.)
chop
lt?php text " . ... .email me your email... .
. " // Chop echo "Text "."".text."" ec
ho "ltbrgt" echo "Trim "."".chop(text)."" e
cho "ltbrgt" echo "Trim . and space
"."".chop(text, ". ")."" echo "ltbrgt" echo
"Trim e,m,a,i,l,. and space "."".chop(text,
"email. ")."" ?gt
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PHP StringFormatting (ctn.)
chop
Chop behaves exactly like RTRIM. Chop does not
change the variable itself and therefore the
variable will remain intact.
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PHP StringFormatting (ctn.)

• Case Changing These functions will change the
  case of a particular character to lower or upper.
• Usually we use these functions to format the
  users input data received by forms.
• Remember that UNIX systems are case sensitive!

strtoupper (string) strtolower (string) ucfirst
(string) ucwords (string)
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PHP StringFormatting (ctn.)
strtoupper
strtolower
lt?php text "Hello World!" echo "Text
".text // strtoupper changes all of the
characters to upper case echo "ltbrgt" echo
"strtoupper ".strtoupper(text) //
strtoupper changes all of the characters to upper
case echo "ltbrgt" echo "strtolower
".strtolower(text) ?gt
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PHP StringFormatting (ctn.)
strtoupper
strtolower
STRTOUPPER makes a string upper case. STRTOLOWER
makes a string lower case.
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PHP StringFormatting (ctn.)
ucfirst
ucwords
lt?php text "this is my sentence!" echo
"Text ".text // ucfirst make a string's
first character uppercase echo "ltbrgt" echo
"ucfirst ".ucfirst(text) // ucwords
Uppercase the first character of each word in a
string echo "ltbrgt" echo "ucwords
".ucwords(text) ?gt
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PHP StringFormatting (ctn.)
ucfirst
ucwords
UCFIRST make a string's first character
uppercase UCWORDS Uppercase the first character
of each word in a string
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PHP StringFormatting (ctn.)

• These commands are recommended for reading
• print()
• printf()
• sprintf()
• print_r()
• nl2br()
• addslashes()
• stripslashes()
• Please refer to the following link for more
  information
• http//ca.php.net/manual/en/ref.strings.php

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PHP StringJoinSplit

• Joining These functions will join elements of an
  array to make a string.
• Splitting These functions will split a string
  and create an array from the fragments.

implode (seperator, array elements) join
(seperator, array elements)
explode (seperator, string, limit) split
(regular expression, string) substr (string,
start position, length)
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PHP StringJoinSplit (ctn.)
implode
lt?php text array ("Peter", "Mike", "Brian",
"Robin") print_r(text) // implode joins
array elements with a string echo "ltbrgt" echo
"implode " . implode(",", text) ?gt
In this case , (comma) is the delimiter or the
glue to join the array elements.
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PHP StringJoinSplit (ctn.)
implode
IMPLODE joins array elements with a string. JOIN
works the same as IMPLODE.
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PHP StringJoinSplit (ctn.)
explode
lt?php text "This is my sentence" //
explode splits a string by the string delimiter
in an array echo "ltbrgt" echo "explode " .
explode(" ", text) echo "ltbrgt" x
explode(" ", text) print_r(x) ?gt
In this case (space) is the delimiter or the
splitter to split the string into fragments of
then putting them as array elements.
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PHP StringJoinSplit (ctn.)
explode
EXPLODE splits a string by the string delimiter
in an array
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PHP StringJoinSplit (ctn.)
substr
lt?php text "This is my sentence" echo
"ltpregt" echo "Text " . text echo
"ltbrgt" echo "......0123456789012345678" echo
"lt/pregt" // substr returns part of a
string echo "ltbrgt" echo "substr start 1 " .
substr(text, 1) echo "ltbrgt" echo "substr
start 5 " . substr(text, 5) echo "ltbrgt"
echo "substr start 0 length 4 " . substr(text,
0, 4) echo "ltbrgt" echo "substr start 2 length
4 " . substr(text, 2, 4) echo "ltbrgt" echo
"substr start -1 length 1 " . substr(text, -1,
1) ?gt
substr (string, num1, num2) The first number is
the starting position in the string and the
second number is the length of the substring.
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PHP StringJoinSplit (ctn.)
substr
SUBSTR returns part of a string
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PHP StringComparision

• strcmp() will compare two given strings and
  returns lt 0 if str1 is less than str2 gt 0 if
  str1 is greater than str2, and 0 if they are
  equal.
• strcasecmp() is the non-case sensitive version of
  it.
• strlen() returns the length of a string

strcmp (string_1, string_2) strcasecmp
(string_1, string_2)
strlen (string)
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PHP StringComparision (ctn.)
strcmp
strcasecmp
lt?php text1 "ABC" text2 "abc" echo
"Text1 " . text1 echo "ltbrgt" echo "Text2
" . text2 echo "ltbrgt" // strcmp is a
binary safe comparision echo "ltbrgt" echo
"strcmp " . strcmp(text1, text2) //
strcasecmp is a binary safe case insensitive
comparision echo "ltbrgt" echo "strcasecmp "
. strcasecmp(text1, text1) ?gt
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PHP StringComparision (ctn.)
strcmp
strcasecmp
STRCMP resulted in -32 because the ASCI code of
A is 32 numbers below a
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PHP StringComparision (ctn.)
strlen
lt?php text "This is my sentence" echo
"ltpregt" echo "Text " . text echo
"ltbrgt" echo "......0123456789012345678" echo
"lt/pregt" // strlen gets the string's
length echo "ltbrgt" echo "strlen " .
strlen(text) ?gt
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PHP StringComparision (ctn.)
strlen
STRLEN shows the length of a string
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PHP StringMatchReplace

• Match The commands match a specific substring in
  a longer string.
• Replace The commands replace a substring of a
  longer string.

strstr (string, substring) strchr (string,
substring) strrchr (string, substring) stristr
(string, substring)
str_replace (sub_string, sub_new, string)
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PHP StringMatchReplace (ctn.)
strstr
lt?php email "yourname_at_yoursite.com" echo
"Email " . email echo "ltbrgt" // strstr
finds the first occurrence of a string echo
"ltbrgt" echo "strstr for _at_ " . strstr(email,
"_at_") echo "ltbrgt" echo "strstr for . " .
strstr(email, ".") echo "ltbrgt" echo "strstr
for r " . strstr(email, "r") ?gt
In these case _at_, . and r have been used as the
determining characters.
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PHP StringMatchReplace (ctn.)
strstr
STRSTR finds the first occurrence of a
string STRCHR is the same as STRSTR STRISTR is
the case insensitive of STRSTR
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PHP StringMatchReplace (ctn.)
strrchr
lt?php email "yourname_at_yoursite.com" echo
"Email " . email echo "ltbrgt" // strrchr
finds the last occurrence of a character in a
string echo "ltbrgt" echo "strrchr for _at_ " .
strrchr(email, "_at_") echo "ltbrgt" echo
"strrchr for . " . strrchr(email, ".") echo
"ltbrgt" echo "strrchr for r " .
strrchr(email, "r") ?gt
In these case _at_, . and r have been used as the
determining characters.
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PHP StringMatchReplace (ctn.)
strrchr
STRRCHR finds the last occurrence of a character
in a string, therefore for the last case it did
not find rname_at_yoursite.com as it always looks
for the last occurance.
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PHP StringMatchReplace (ctn.)
str_replace
lt?php text "Peter is a teacher. Peter goes to
the school everyday." echo "Text " . text
echo "ltbrgt" // str_replace replaces all
occurrences of the // search string with the
replacement string echo "ltbrgt" echo
"str_replace replacing Peter with Mark " .
str_replace("Peter", "Mark", text) ?gt
In these case Peter has been replaced with
Mark anywhere in the string.
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PHP StringMatchReplace (ctn.)
str_replace
STR_REPLACE replaces all occurrences of the
search string with the replacement string
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Summary

• PHP String Manipulations
• Formatting Strings
• Joining and Splitting Strings
• Comparing Strings
• Match and Replace Substrings

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Next Sessions

• PHP Array Manipulations
• PHP Conditions
• PHP Loops
• PHP Functions
• PHP Cookies
• PHP SSI
• PHP Forms
• PHP/MySQL Integration

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Exercise

• Please refer to the available text file in the
  slides section for session 11 on the tutorials
  website
• http//flame.cs.dal.ca/kharrazi/teaching/hinf_62
  20/slides.php

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Tutorial References

• Readings
• PHP Reference
• http//ca.php.net/docs.php
• Online HTML Resources
• http//www.w3schools.com/html/default.asp
• Online PHP Resources
• http//www.w3schools.com/php/default.asp