PHP Exercises: Create a new string taking the first 3 characters of a given string and return the string with the 3 characters added at both the front and back

Last update on May 28 2025 09:29:35 (UTC/GMT +8 hours)

11. Add First 3 Characters Front and Back

Write a PHP program to create a new string taking the first 3 characters of a given string and return the string with the 3 characters added at both the front and back. If the given string length is less than 3, use whatever characters are there.

Sample Solution:

PHP Code :

<?php
// Define a function named "test" that takes a parameter $str
function test($str) 
{
    // Use an if-else statement to check if the length of $str is less than 3
    if (strlen($str) < 3) {
        // If true, concatenate $str with itself twice and return the result
        return $str . $str . $str;
    } else {
        // If false, use substr to get the first three characters of $str
        $front = substr($str, 0, 3);
        
        // Concatenate $front, $str, and $front, then return the result
        return $front . $str . $front;
    }
}

// Call the test function with argument "Python" and echo the result
echo test("Python") . "\n";

// Call the test function with argument "JS" and echo the result
echo test("JS") . "\n";

// Call the test function with argument "Code" and echo the result
echo test("Code") . "\n";
?>

Explanation:

• Function Definition:
• The test function takes one parameter, $str.
• Length Check:
• If the length of $str is less than 3 characters:
  • Concatenate $str with itself twice (creating a string of three copies) and return this result.
• If $str has 3 or more characters:
  • Extract the first three characters of $str and store it in $front.
• Concatenate $front, $str, and $front again, and return this new string.
• Function Calls and Output:
• First Call: test("Python")
• $str has more than 3 characters, so $front is "Pyt".
• Returns "PytPythonPyt".
• Second Call: test("JS")
• $str has fewer than 3 characters, so returns "JSJSJS".
• Third Call: test("Code")
• $str has more than 3 characters, so $front is "Cod".
• Returns "CodCodeCod".

Output:

PytPythonPyt
JSJSJS
CodCodeCod

Visual Presentation:

Flowchart:

For more Practice: Solve these Related Problems:

• Write a PHP script to form a new string by adding the first three characters of the input string to both its beginning and end, handling short strings appropriately.
• Write a PHP function that takes a string and, if its length is less than three, repeats the entire string as a prefix and suffix.
• Write a PHP program to build a new string by extracting the first three characters and appending them to the front and back of the original string.
• Write a PHP script to replicate the first three characters as both a header and trailer for the given string using concatenation.

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