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PHP Exercises: Count a substring of length 2 appears in a given string and also as the last 2 characters of the string

PHP Basic Algorithm: Exercise-31 with Solution

Write a PHP program to count a substring of length 2 appears in a given string and also as the last 2 characters of the string. Do not count the end substring.

Sample Solution:

PHP Code :

<?php
function test($s)
{
    $last_two_char = substr($s, strlen($s)-2, 2);
    $ctr = 0;

    for ($i = 0; $i < strlen($s)-2; $i++)
        {
           if (substr($s, $i, 2) == $last_two_char) 
           $ctr = $ctr +1;
        }
    return $ctr;
 }

echo test("abcdsab")."\n";
echo test("abcdabab")."\n";
echo test("abcabdabab")."\n";
echo test("abcabd")."\n";

Sample Output:

1
2
3
0

Pictorial Presentation:

PHP Basic Algorithm Exercises: Count a substring of length 2 appears in a given string and also as the last 2 characters of the string.

Flowchart:

Flowchart: Count a substring of length 2 appears in a given string and also as the last 2 characters of the string.

PHP Code Editor:

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Previous: Write a PHP program to create a string like "aababcabcd" from a given string "abcd".
Next: Write a PHP program to check a specified number is present in a given array of integers.

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PHP: Tips of the Day

$_REQUEST: This SuperGlobal Variable is used to collect data submitted by a HTML Form

Example:

This code save in a php file and run in the browser.

<!DOCTYPE html> 
<html> 
<body> 
  
<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>"> 
 NAME: <input type="text" name="user"> 
 <button type="submit">SUBMIT</button> 
</form> 
<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") { 
    $name = htmlspecialchars($_REQUEST['user']); 
    if(empty($name)){ 
        echo "Name is empty"; 
    } else { 
        echo $name; 
    } 
} 
?> 
</body> 
</html> 

Output:

Owen