PHP Exercises: Replace a string "Python" with "PHP" and "Python" with "PHP" in a given string

Last update on April 19 2025 11:49:24 (UTC/GMT +8 hours)

63. Swap PHP and Python

Write a PHP program to replace a string "Python" with "PHP" and "Python" with " PHP" in a given string.

Input: English letters (including single byte alphanumeric characters, blanks, symbols) are given on one line. The length of the input character string is 1000 or less.

Pictorial Presentation:

Sample Solution:

PHP Code:

<?php
// Read input from standard input and remove leading/trailing whitespaces
$str = trim(fgets(STDIN));

// Replace occurrences of 'Python' with '@ython' and 'PHP' with 'Python'
$str = str_replace(array('Python', 'PHP'), array('@ython', 'Python'), $str);

// Replace '@ython' with 'PHP' to get the final result
echo str_replace('@ython', 'PHP', $str), PHP_EOL;

?>

Explanation:

• Read Input:
• The code reads a line of input from standard input and removes any leading or trailing whitespace using trim(fgets(STDIN)).
• Replace Words:
• It uses str_replace to perform multiple replacements:
• It replaces occurrences of the string 'Python' with '@ython'.
• It replaces occurrences of the string 'PHP' with 'Python'.
• Final Replacement:
• After the initial replacements, it performs a second str_replace to replace '@ython' with 'PHP'.
• Output the Result:
• Finally, it outputs the modified string with echo, followed by a newline (PHP_EOL).

Sample Input:
PHP is popular than Python

Sample Output:

Python is popular than PHP.

Flowchart:

For more Practice: Solve these Related Problems:

• Write a PHP script to swap the occurrences of "PHP" and "Python" in a string using temporary placeholders.
• Write a PHP script to exchange two keywords in a given sentence without performing sequential replacements.
• Write a PHP function to replace "PHP" with "Python" and vice versa ensuring overlapping replacements are handled.
• Write a PHP script to perform a bidirectional swap on two substrings within a string dynamically.

PHP Code Editor:

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