PHP Challenges: Find the length of the last word in a string

Last update on June 03 2025 13:00:02 (UTC/GMT +8 hours)

Input : PHP Exercises

Write a PHP program to find the length of the last word in a string.

Explanation :

PHP: Find the length of the last word in a string

Sample Solution :

PHP Code :

<?php
// Function to calculate the length of the last word in a string
function length_of_last_word($s)
{
    // Check if the string is empty or contains only whitespace characters
    if (strlen(trim($s)) == 0)
    {
        return "Blank String";
    }

    // Split the string into words
    $words = explode(' ', $s);

    // If there are multiple words, return the length of the last word
    if (sizeof($words) > 1)
        return strlen(substr($s, strrpos($s, ' ') + 1));
    else
        return "Single word";
}

// Test cases
print_r(length_of_last_word("PHP Exercises") . "\n");
print_r(length_of_last_word("PHP") . "\n");
print_r(length_of_last_word("") . "\n");
print_r(length_of_last_word("  ") . "\n");
?>

Explanation:

Here is a brief explanation of the above PHP code:

Function definition (length_of_last_word):

The function "length_of_last_word()" takes a string ''$s' as input.
It first checks if the string is empty or contains only whitespace characters. If so, it returns "Blank String".

Inside the function:

If the string is not empty or contains only whitespace characters, it splits the string into words using the "explode()" function.
It checks if there are multiple words in the string. If there are, it extracts the last word using "substr()" and "strrpos()" functions, and returns its length.
If there's only one word in the string, it returns "Single word".

Function Call & Testing:

The "length_of_last_word()" function is tested with different input strings, including strings with multiple words, single word, empty string, and whitespace characters.
Finally "print_r()" function prints the length of the last word or appropriate message.

Sample Output:

9                                                           
Single word                                                 
Blank String                                                
Blank String

Flowchart:

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