Word Boundry "b" metacharacter in Regular Expression.
What is Word Boundry?
Explanation
A word boundry is the boundry between a word character and a non-word character.The word characters are "[a-zA-Z0-9_]" all other characters are non word characters like the ",', etc. The length of word boundry is always "zero".
string = "hiox india"
"/bhiox" - Match boundry between double quotes, the word "hiox".
"/hioxb" - Match boundry between the word "hiox", the space.
<?php
$name = "sam paul christ dany";
if (preg_match("/samb/", $name))
echo "Pattern matches!";
else
echo "Pattern not matched!";
?> Result :
Pattern matches!
In the above example the word "sam" and the space next to it is matched.
#! C:programfilesperlbinperl
print "content-type: text/htmlnn";
$name= "sam-paul-christ-dany";
if ($name =~ m/sambpaul/)
{print "The name format matched!";}
else
{print "The name format not matched!";} Result :
The name format matched!
In the above example the pattern "sambpaul" does not match since the word boundry is found for the word "sam" and "-". so when matching other characters "paul" specify non word character "-" too as "samb-paul" in the pattern that should match.
string = "hiox india"
"/bhiox" - Match boundry between double quotes, the word "hiox".
"/hioxb" - Match boundry between the word "hiox", the space.
PHP Example:
<?php
$name = "sam paul christ dany";
if (preg_match("/samb/", $name))
echo "Pattern matches!";
else
echo "Pattern not matched!";
?>
Pattern matches!
In the above example the word "sam" and the space next to it is matched.
Perl Example:
#! C:programfilesperlbinperl
print "content-type: text/htmlnn";
$name= "sam-paul-christ-dany";
if ($name =~ m/sambpaul/)
{print "The name format matched!";}
else
{print "The name format not matched!";}
The name format matched!
In the above example the pattern "sambpaul" does not match since the word boundry is found for the word "sam" and "-". so when matching other characters "paul" specify non word character "-" too as "samb-paul" in the pattern that should match.
