How to get string between two characters in PHP ?

A string is a sequence of characters stored in the incremental form in PHP. A set of characters, one or many can lie between any two chosen indexes of the string. The text between two characters in PHP can be extracted using the following two methods : 

Approach 1: Using substr() Method:

The substr() method is used to retrieve a substring of the original string. It takes as indexes the start and end indexes and extracts the part of the string lying between the indexes. In order to retrieve the substring from the beginning, the start-index is chosen to be 0. 

substr(string, startIndex, lengthStr)

Parameters: 

• string: In this parameter, we pass the original string or the string that needs to be cut or modified. It is a mandatory parameter.
• startIndex: It refers to the position of the original string from where the part needs to be extracted. In this, we pass an integer. If the integer is positive it refers to the start of the position in the string from the beginning. If the integer is negative then it refers to the start of the position from the end of the string. This is also a mandatory parameter.
• lengthStr: It is an optional parameter of integer type. It refers to the length of the part of the string that needs to be cut from the original string. If the integer is positive, it refers to start from start_position and extract length from the beginning. If the integer is negative then it refers to start from start_position and extract the length from the end of the string. If this parameter is not passed, then the substr() function will return the string starting from start_position till the end of the string.

<?php
  
// Declaring a string variable
$str = "Hi! This is geeksforgeeks";
echo("Original String : ");
echo($str . "\n");

$final_str = substr($str, 4, 7);

echo("Modified String : ");
echo($final_str);
?>

Original String : Hi! This is geeksforgeeks
Modified String : This is

Approach 2: Using for loop and str_split() Method:

The str_split() method is used to split the specified string into an array, where the elements are mapped to their corresponding indexes. The indexes of the array begin with 0. 

array_split( string )

A loop iteration is performed over the array length. Every time the iteration is performed the index is checked if it lies between the start and end index. If it lies in the range, the character is extracted.  

<?php

// Declaring a string variable
$str = "Hi! This is geeksforgeeks";
echo("Original String : ");
echo($str . "\n");

// Define the start index
$start = 5;

// Define the end index
$end = 8;
$arr = str_split($str);

echo("Modified String : ");

for($i = 0; $i < sizeof($arr); $i++) {
    if($i >= $start && $i <= $end) {
        print($arr[$i]);
    }
}
?>

Original String : Hi! This is geeksforgeeks
Modified String : his 

Approach 3: Using preg_match()

Using preg_match() in PHP, you can extract a substring between two characters by defining a regular expression pattern that matches the content between the specified delimiters.

Example

<?php
function getStringBetween($string, $startChar, $endChar) {
    $pattern = "/".preg_quote($startChar, '/')."(.*?)".preg_quote($endChar, '/')."/";
    preg_match($pattern, $string, $matches);
    return $matches[1] ?? '';
}

$string = "Hello [start]World[end]!";
echo getStringBetween($string, "[start]", "[end]") . PHP_EOL; // Output: World
?>

World

Approach 4: Using strpos() and substr()

The strpos() function is used to find the position of the first occurrence of a substring in a string. By locating the start and end characters' positions, you can then use substr() to extract the substring between these positions.

Example

<?php
  
// Declaring a string variable
$str = "Hi! This is geeksforgeeks";
echo("Original String : ");
echo($str . "\n");

// Find the position of the substring "This"
$start_pos = strpos($str, "This");

// If the substring is found, extract it
if ($start_pos !== false) {
    $final_str = substr($str, $start_pos, 7);
    echo("Modified String : ");
    echo($final_str);
} else {
    echo("Substring not found.");
}
?>

Original String : Hi! This is geeksforgeeks
Modified String : This is