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PHP Regular Expression Exercises: Checks whether a string contains another string

PHP regular expression: Exercise-1 with Solution

Write a PHP script that checks whether a string contains another string.

Visual Presentation:

PHP Regular Expression Exercise: Checks whether a string contains another string

Sample Solution:

PHP Code:

<?php
// Define the regular expression pattern to match 'fox' preceded by a word character and followed by a space
$pattern = '/[^\w]fox\s/';

// Use preg_match function to check if the pattern matches the given string
if (preg_match($pattern, 'The quick brown fox jumps over the lazy dog')) {
    // If 'fox' is found in the string, echo that it is present
    echo "'fox' is present..."."\n";
} else {
    // If 'fox' is not found in the string, echo that it is not present
    echo "'fox' is not present..."."\n";
}
?>

Output:

'fox' is present... 

Explanation:

In the exercise above,

  • A regular expression pattern is defined using the '$pattern' variable. The pattern /[^\w]fox\s/ is used, which matches the word "fox" preceded by a non-word character and followed by a space.
  • The "preg_match()" function checks if the pattern matches the given string 'The quick brown fox jumps over the lazy dog'.
  • If the pattern matches the string, meaning the word "fox" is found as per the defined pattern, it echoes "'fox' is present...".
  • If the pattern doesn't match the string, meaning the word "fox" is not found as per the defined pattern, it echoes "'fox' is not present...".

Flowchart :

Flowchart: Checks whether a string contains another string.

PHP Code Editor:

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