PHP strpos() and stripos() Functions
Last Updated : 09 May, 2022
In this article, we will see how to find the position of the first occurrence of a string in another string using strpos() and stripos() Functions in PHP, & will see their implementation through the examples.
Both the strpos() and stripos() Functions in PHP are binary-safe which means the function will handle its input as a raw byte stream and disregard every textual content it may contain. Here, the function will work correctly while passing arbitrary binary data ie., a string having non-ASCII bytes &/or null-bytes.
strpos() Function: This function helps us to find the position of the first occurrence of a string in another string. This returns an integer value of the position of the first occurrence of the string. This function is case-sensitive, which means that it treats upper-case and lower-case characters differently.
Syntax:
strpos(original_str, search_str, start_pos);
Parameter value: Out of the three parameters specified in the syntax, two are mandatory and one is optional. The three parameters are described below:
- original_str: This is a mandatory parameter that refers to the original string in which we need to search the occurrence of the required string.
- search_str: This is a mandatory parameter that refers to the string that we need to search.
- start_pos: This is an optional parameter that refers to the position of the string from where the search must begin.
Return Type: This function returns an integer value that represents the index of original_str where the string search_str first occurs.
Example: This example illustrates the strpos() function that specifies the position of the occurrence of a string in another string.
PHP <?php // PHP code to search for a specific string's position // first occurrence using strpos() case-sensitive function function Search($search, $string) { $position = strpos($string, $search, 5); if (is_numeric($position)) { return "Found at position: " . $position; } else { return "Not Found"; } } // Driver Code $string = "Welcome to GeeksforGeeks"; $search = "Geeks"; echo Search($search, $string); ?> Output:
Found at position 11
stripos() Function: This function also helps us to find the position of the first occurrence of a string in another string. This returns an integer value of the position of the first occurrence of the string. This function is case-insensitive, which means it treats both upper-case and lower-case characters equally. This function works similarly as strpos(), the difference is that it is case in-sensitive whereas strpos() is case sensitive.
Syntax:
stripos(original_str, search_str, start_pos);
Parameter value: Out of the three parameters specified in the syntax, two are mandatory and one is optional.
- original_str: This is a mandatory parameter that refers to the original string in which we need to search the occurrence of the required string.
- search_str: This is a mandatory parameter that refers to the string that we need to find.
- start_pos: This is an optional parameter that refers to the position of the string from where the search must begin.
Return Type: This function returns an integer value that represents the index of original_str where the string search_str first occurs.
Example: This example illustrates the stripos() function that specifies the position of the occurrence of a string in another string.
PHP <?php // PHP code to search for a specific string // first occurrence using stripos() case-insensitive function function Search($search, $string) { $position = stripos($string, $search, 5); if ($position == true) { return "Found at position " . $position; } else { return "Not Found"; } } // Driver Code $string = "Welcome to GeeksforGeeks"; $search = "geeks"; echo Search($search, $string); ?> Output:
Found at position 11
Let us understand these functions in a tabular form -:
| | strpos() | stripos() |
| 1. | The strpos() function finds the position of the first occurrence of a string inside another string. | The stripos() function finds the position of the first occurrence of a string inside another string. |
| 2. | It is case-sensitive function. | It is case-insensitive function. |
| 3. | Its syntax is -: strpos(string,find,start) | Its syntax is -: stripos(string,find,start) |
| 4. | This function returns the position of the first occurrence of a string inside another string else it returns false if the string does not found. | It returns the position of the first occurrence of a string inside another string else it returns false if the string does not found. |
| 5. | It is supported in PHP version 4.0+ | It is supported in PHP version 5.0+ |