PHP Exercises: Create a new string from a given string. If the first or first two characters is 'a', return the string without those 'a' characters otherwise return the original given string

PHP Basic Algorithm: Exercise-85 with Solution

Write a PHP program to create a new string from a given string. If the first or first two characters is 'a', return the string without those 'a' characters otherwise return the original given string.

Sample Solution:

PHP Code :

<?php
// Define a function named 'test' that manipulates a string based on the presence of the character 'a'
function test($s1)
{ 
    // Check if the length of $s1 is 1 and if the character is 'a'
    if (strlen($s1) == 1 && substr($s1, 0, 1) == "a")
    {
        // Remove the character 'a' from $s1
        $s1 = substr($s1, 1);
    }

    // Check if the length of $s1 is greater than 1
    if (strlen($s1) > 1)
    {
        // Check if the second character is 'a'
        if (substr($s1, 1, 1) == "a")
        {
            // Remove the second character from $s1
            $s1 = substr($s1, 0, 1) . substr($s1, 2);
        }

        // Check if the first character is 'a'
        if (substr($s1, 0, 1) == "a")
        {
            // Remove the first character from $s1
            $s1 = substr($s1, 1);
        }
    }

    // Return the modified or original string
    return $s1;
}

// Test the 'test' function with different strings, then display the results
echo test("abcab") . "\n";
echo test("Python") . "\n";
echo test("aacda") . "\n";
echo test("jython") . "\n";
?>

Explanation:

• Function Definition:
• The function test is defined with one parameter:
• $s1: the input string to be processed.
• Single Character Check:
• The function checks:
• Condition: If the length of $s1 is 1 and if that character is 'a':
• This is done using strlen($s1) == 1 and substr($s1, 0, 1) == "a".
• Action: If the condition is true, the character 'a' is removed from $s1 using:
• substr($s1, 1).
• Multiple Characters Check:
• The function checks:
• Condition: If the length of $s1 is greater than 1:
• This is done using strlen($s1) > 1.
• Second Character Check:
• Within this check, the function checks:
• Condition: If the second character of $s1 is 'a':
• This is done using substr($s1, 1, 1) == "a".
• Action: If the condition is true, the second character is removed from $s1 using:
• substr($s1, 0, 1) . substr($s1, 2) (concatenating the first character with the substring from the third character onward).
• First Character Check:
• The function then checks:
• Condition: If the first character of $s1 is 'a':
• This is done using substr($s1, 0, 1) == "a".
• Action: If the condition is true, the first character is removed from $s1 using:
• substr($s1, 1).
• Return Value:
• The function returns the modified string (with 'a' removed if applicable) or the original string if no modifications were made.

Output:

bcab
Python
cda
jython

Flowchart:

PHP Code Editor:

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