26. String Manipulation Functions
PHP offers an extensive library of functions for extracting, transforming, and searching strings.
1. Substrings
substr() extracts a part of a string.
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2. Substring: " . $fox; // Output: fox. ?>2. Searching and Replacing
| Function | Description |
|---|---|
str_replace(search, replace, subject) | Replaces all occurrences of the search string with the replacement string. |
strpos(haystack, needle) | Finds the position of the first occurrence of a string. |
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3. Replace: " . $new_text; // Output: I love PHP. // Find the position of 'love' $pos = strpos($text, "love"); echo "4. Position of 'love': " . $pos; // Output: 2 ?>
3. Trimming Whitespace
Whitespace (spaces, tabs, newlines) can cause issues, especially with user input. trim() removes it.
| Function | Description |
|---|---|
trim($str) | Removes whitespace from both ends. |
ltrim($str) | Removes whitespace from the left side. |
rtrim($str) | Removes whitespace from the right side. |
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5. Cleaned string length: " . strlen($cleaned); // Should be 18, not 24 ?>