How to prepend a string in PHP?

Last Updated : 17 Jul, 2024

We have given two strings and the task is to prepend a string str1 with another string str2 in PHP. There is no specific function to prepend a string in PHP. To do this task, we have the following operators in PHP:

Below are the methods to prepend a string in PHP

Table of Content

Using Concatenation Operator(“.”)
Using Concatenation assignment operator (“.=”)
Using sprintf()

Method 1: Using Concatenation Operator(“.”)

The Concatenation operator is used to prepend a string str1 with another string str2 by concatenation of str1 and str2.

Syntax:

$x . $y

Example :

<?php
// PHP program to prepend a string 


// Function to prepend a string 
function prepend_string ($str1, $str2){
    
    // Using concatenation operator (.)
    $res = $str1 . $str2;
    
    // Returning the result 
    return $res;
    }

// Given string
$str1 = "Geeksforgeeks"; 
$str2 = "Example"; 

// Function Call
$str = prepend_string ($str1, $str2); 

// Printing the result
echo $str; 
?>

Output

GeeksforgeeksExample

Method 2: Using Concatenation assignment operator (“.=”)

The Concatenation assignment operator is used to prepend a string str1 with another string str2 by appending the str2 to the str1.

Syntax:

$x .= $y

Example :

<?php
// PHP program to prepend a string 

// Function to prepend a string 
function prepend_string ($str1, $str2) {
    
    // Using Concatenation assignment
    // operator (.=)
    $str1 .= $str2;
    
    // Returning the result 
    return $str1;
}

// Given string
$str1 = "Geeksforgeeks"; 
$str2 = "Example"; 

// Function call
$str = prepend_string ($str1, $str2); 

// Printing the result
echo $str; 
?>

Output

GeeksforgeeksExample

Method 3: Using sprintf()

The sprintf() function formats a string according to a specified format. By specifying a format that includes both strings in the desired order, you can prepend one string with another.

Example

<?php
// Define the strings
$str1 = "world!";
$str2 = "Hello, ";

// Use sprintf() to prepend str1 with str2
$result = sprintf('%s%s', $str2, $str1);

// Output the result
echo $result . "\n"; 
?>