TOKENIZE a STRING.
<?php
str strtok ( str $str , str $token )
where,
$str = The STRING being split up into tokens
$token = The delimiter used when splitting up $str
?>
<?php
str strtok ( str $token )
where,
$token = The delimiter used when splitting up a STRING
?>
EXERCISE
<?php
$str01 = 'Every dog has his day.';
$tks01 = ' ';
$strtk01 = strtok($str01, $tks01)
. ' ' . strtok($tks01) . ' ' . strtok($tks01)
. ' ' . strtok($tks01) . ' ' . strtok($tks01);
echo $strtk01 . '<br>';
?>
EXERCISE
<?php
$str02 = 'https://php.net/manual/en/function.strtok.php';
echo $str02 . '<br><br>';
$tks02 = '\ /. ';
$strtk02 = strtok($str02, $tks02)
. ' ' . strtok($tks02) . ' ' . strtok($tks02)
. ' ' . strtok($tks02) . ' ' . strtok($tks02)
. ' ' . strtok($tks02) . ' ' . strtok($tks02);
echo $strtk02 . '<br>';
?>
EXERCISE
<?php
/*
* Testing strtok() : basic functionality
*/
echo "Testing strtok() : basic functionality.<br>";
// Initialize all required variables
$str = 'This testcase test strtok() function.';
$token = ' ().';
echo "<br>The Input string is:<br>\"$str\"<br>";
echo '<br><br>';
echo "The token string is:<br>\"$token\"<br>";
// using strtok() with $str argument
echo "<br><br>Token 1;<br>";
var_dump( strtok($str, $token) );
for( $i = 2; $i <=7; $i++ ) {
echo "<br><br>Token $i:<br>";
var_dump( strtok($token) );
}
?>
EXERCISE
<?php
/*
* Testing strtok() : with heredoc strings
*/
echo "Testing strtok() : with heredoc strings.<br>";
// defining different heredoc strings
$empty_heredoc = <<<EOT
EOT;
$heredoc_with_newline = <<<EOT
\n
EOT;
$heredoc_with_characters = <<<EOT
first line of heredoc string
second line of heredoc string
third line of heredocstring
EOT;
$heredoc_with_newline_and_tabs = <<<EOT
hello\tworld\nhello\nworld\n
EOT;
$heredoc_with_alphanumerics = <<<EOT
hello123world456
1234hello\t1234
EOT;
$heredoc_with_embedded_nulls = <<<EOT
hello\0world\0hello
\0hello\0
EOT;
$heredoc_strings = [
$empty_heredoc,
$heredoc_with_newline,
$heredoc_with_characters,
$heredoc_with_newline_and_tabs,
$heredoc_with_alphanumerics,
$heredoc_with_embedded_nulls
];
// loop through each element of the array
// and check the working of strtok()
// when supplied with different string values
$count = 1;
foreach($heredoc_strings as $string) {
echo "<br><br>Iteration: $count<br>";
var_dump( strtok($string, "5o\0\n\t") );
echo '<br>';
for($counter = 1; $counter <= 10; $counter++) {
var_dump( strtok("5o\0\n\t") );
echo '<br>';
}
$count++;
}
?>
EXERCISE
<?php
/*
* Testing strtok() : with embedded nulls in the strings
*/
echo "Testing strtok() : with embedded nulls in the strings.<br>";
// defining varous strings with embedded nulls
$strings_with_nulls = array(
"\0",
'\0',
"hello\0world",
"\0hel\0lo",
"hello\0",
"\0\0hello\tworld\0\0",
"\\0he\0llo\\0",
'hello\0\0'
);
// loop through each element of the array
// and check the working of strtok()
// when supplied with different string values
$counter = 1;
foreach( $strings_with_nulls as $string ) {
echo "<br><br>Iteration: $counter<br>";
var_dump( strtok($string, "\0") );
echo '<br>';
for($count = 1; $count <= 5; $count++) {
var_dump( strtok("\0") );
echo '<br>';
}
$counter++;
}
?>
EXERCISE
<?php
/*
* Testing strtok() : with miscellaneous
* combinations of string and token
*/
echo "Testing strtok() : with miscellaneous inputs.<br>";
// defining arrays for input strings and tokens
$string_array = array(
"HELLO WORLD",
"hello world",
"_HELLO_WORLD_",
"/thello/t/wor/ttld",
"hel/lo/t/world",
"one:$:two:!:three:#:four",
"\rhello/r/wor\rrld",
chr(0),
chr(0).chr(0),
chr(0).'hello'.chr(0),
'hello'.chr(0).'world'
);
$token_array = array(
"wr",
"hello world",
"__",
"t/",
'/t',
":",
"\r",
"\0",
"\0",
"\0",
"\0",
);
// loop through each element of the array
// and check the working of strtok()
// when supplied with different string
// and token values
$counter =1;
foreach( $string_array as $string ) {
echo "<br><br>Iteration: $counter<br>";
var_dump( strtok($string, $token_array[$counter-1]) );
echo '<br>';
for( $count = 1; $count <=5; $count++ ) {
var_dump( strtok($token_array[$counter-1]) );
echo '<br>';
}
$counter++;
}
?>
EXERCISE
<?php
/*
* Testing strtok() : with invalid escape
* sequences in token
*/
echo "Testing strtok() :
with invalid escape sequences in token.<br>";
// defining arrays for input strings and tokens
$string_array = array(
"khellok worldk",
"\khello\k world\k",
"/khello\k world/k",
"/hellok/ world"
);
$token_array = array(
"k",
"/ ",
"/k",
"\k",
"\\\\\\\k\h\\e\l\o\w\r\l\d"
);
// loop through each element of the array
// and check the working of strtok()
// when supplied with different string
// and token values
$counter =1;
foreach( $string_array as $string ) {
echo "<br><br>Iteration: $counter<br>";
foreach( $token_array as $token ) {
var_dump( strtok($string, $token) );
echo '<br>';
for( $count = 1; $count <=3; $count++ ) {
var_dump( strtok($token) );
echo '<br>';
}
echo "<br>";
}
$counter++;
}
?>
EXERCISE
<?php
/*
* Testing strtok() : modifying the input string
* while it is getting tokenised
*/
echo "Testing strtok() :
with modification of input string
in between tokenising.<br>";
$str = "this is a sample string";
$token = " ";
echo "<br><br>Given:<br>\"$str\"<br>and<br>\"$token\"";
echo "<br><br>Testing strtok() when string being
tokenised is prefixed with another
string in between the process:<br>";
var_dump( strtok($str, $token) );
// adding a string to the input string
// which is being tokenised
$str = "extra string ".$str;
for( $count = 1; $count <=6; $count++ ) {
echo "<br><br>Token $count is: <br>";
var_dump( strtok($token) );
echo "<br>Input str is:<br>\"$str\"<br>";
}
echo "<br><br>Testing strtok() when string being
tokenised is suffixed with another
string in between the process:<br>";
var_dump( strtok($str, $token) );
// adding a string to the input string
// which is being tokenised
$str = $str." extra string";
for( $count = 1; $count <=10; $count++ ) {
echo "<br><br>Token $count is;<br>";
var_dump( strtok($token) );
}
?>