PHP | strpos() and stripos() Functions

Last Updated : 15 Apr, 2020

strpos() in PHP

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)

Parameters used:
Out of the three parameters specified in the syntax, two are mandatory and one is optional. The three parameters are described below:

original_str (mandatory): This parameter refers to the original string in which we need to search the occurrence of required string.
search_str (mandatory):This parameter refers to the string that we need to search.
start_pos (optional): Refers to the position of the string from where the search must begin.

Return Type: This function returns an integer value which represents the index of original_str where the string search_str first occurs.

Example:

<?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() in PHP

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 where as strpos() is case sensitive.

Syntax:

stripos(original_str, search_str, start_pos)

Parameters used:
Out of the three parameters specified in the syntax, two are mandatory and one is optional

original_str (mandatory): This parameter refers to the original string in which we need to search the occurrence of required string.
search_str (mandatory): This parameter refers to the string that we need to find.
start_pos (optional):This parameter refers to the position of the string from where the search must begin.

Return Type: This function returns an integer value which represents the index of original_str where the string search_str first occurs.

Example:

<?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 posiion " . $position;
    }
    else{
        return "Not Found";
    }
}
  
// Driver Code
$string = "Welcome to GeeksforGeeks";
$search = "geeks";
echo Search($search, $string);
?>

Output:

Found at position 11

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