concatenation assignment operator in php

Home » PHP Tutorial » PHP Assignment Operators

PHP Assignment Operators

Summary : in this tutorial, you will learn about the most commonly used PHP assignment operators.

Introduction to the PHP assignment operator

PHP uses the = to represent the assignment operator. The following shows the syntax of the assignment operator:

On the left side of the assignment operator ( = ) is a variable to which you want to assign a value. And on the right side of the assignment operator ( = ) is a value or an expression.

When evaluating the assignment operator ( = ), PHP evaluates the expression on the right side first and assigns the result to the variable on the left side. For example:

In this example, we assigned 10 to $x, 20 to $y, and the sum of $x and $y to $total.

The assignment expression returns a value assigned, which is the result of the expression in this case:

It means that you can use multiple assignment operators in a single statement like this:

In this case, PHP evaluates the right-most expression first:

The variable $y is 20 .

The assignment expression $y = 20 returns 20 so PHP assigns 20 to $x . After the assignments, both $x and $y equal 20.

Arithmetic assignment operators

Sometimes, you want to increase a variable by a specific value. For example:

How it works.

• First, $counter is set to 1 .
• Then, increase the $counter by 1 and assign the result to the $counter .

After the assignments, the value of $counter is 2 .

PHP provides the arithmetic assignment operator += that can do the same but with a shorter code. For example:

The expression $counter += 1 is equivalent to the expression $counter = $counter + 1 .

Besides the += operator, PHP provides other arithmetic assignment operators. The following table illustrates all the arithmetic assignment operators:

Concatenation assignment operator

PHP uses the concatenation operator (.) to concatenate two strings. For example:

By using the concatenation assignment operator you can concatenate two strings and assigns the result string to a variable. For example:

• Use PHP assignment operator ( = ) to assign a value to a variable. The assignment expression returns the value assigned.
• Use arithmetic assignment operators to carry arithmetic operations and assign at the same time.
• Use concatenation assignment operator ( .= )to concatenate strings and assign the result to a variable in a single statement.

• PHP String Operators

In PHP, string operators, such as the concatenation operator (.) and its assignment variant (.=), are employed for manipulating and concatenating strings in PHP. This entails combining two or more strings. The concatenation assignment operator (.=) is particularly useful for appending the right operand to the left operand.

Let’s explore these operators in more detail:

Concatenation Operator (.)

The concatenation operator (.) is utilized to combine two strings. Here’s an example:

You can concatenate more than two strings by chaining multiple concatenation operations.

Let’s take a look at another pattern of the concatenation operator, specifically the concatenation assignment operator.

Concatenation Assignment Operator (.=)

The .= operator is a shorthand assignment operator that concatenates the right operand to the left operand and assigns the result to the left operand. This is particularly useful for building strings incrementally:

This is equivalent to $greeting = $greeting . " World!"; .

Let’s see some examples

Examples of Concatenating Strings in PHP

Here are some more advanced examples demonstrating the use of both the concatenation operator (.) and the concatenation assignment operator (.=) in PHP:

Concatenation Operator ( . ):

In this example, the . operator is used to concatenate multiple strings and variables into a single string.

Concatenation Assignment Operator ( .=) :

Here, the .= operator is used to append additional text to the existing string in the $paragraph variable. It is a convenient way to build up a string gradually.

Concatenation Within Iterations:

You can also use concatenation within iterations to build strings dynamically. Here’s an example using a loop to concatenate numbers from 1 to 5:

In this example, the .= operator is used within the for loop to concatenate the current number and a string to the existing $result string. The loop iterates from 1 to 5, building the final string. The rtrim function is then used to remove the trailing comma and space.

You can adapt this concept to various scenarios where you need to dynamically build strings within loops, such as constructing lists, sentences, or any other formatted output.

These examples showcase how you can use string concatenation operators in PHP to create more complex strings by combining variables, literals, iterations and other strings.

Let’s summarize it.

Wrapping Up

PHP provides powerful string operators that are essential for manipulating and concatenating strings. The primary concatenation operator (.) allows for the seamless combination of strings, while the concatenation assignment operator (.=) provides a convenient means of appending content to existing strings.

This versatility is demonstrated through various examples, including simple concatenation operations, the use of concatenation assignment for gradual string construction, and dynamic string building within iterations.

For more PHP tutorials, visit here or visit PHP Manual .

Did you find this article helpful?

Sorry about that. How can we improve it ?

• Facebook -->
• Twitter -->
• Linked In -->
• PHP History
• Install PHP
• Hello World
• PHP Constant
• Predefined Constants
• PHP Comments

PHP Functions

• Parameters and Arguments
• Anonymous Functions
• Variable Function
• Arrow Functions
• Variadic Functions
• Named Arguments
• Callable Vs Callback
• Variable Scope

Control Structures

• If Condition
• If-else Block
• Break Statement

PHP Operators

• Operator Precedence
• PHP Arithmetic Operators
• Assignment Operators
• PHP Bitwise Operators
• PHP Comparison Operators
• PHP Increment and Decrement Operator
• PHP Logical Operators
• Array Operators
• Conditional Operators
• Ternary Operator
• PHP Enumerable
• PHP NOT Operator
• PHP OR Operator
• PHP Spaceship Operator
• AND Operator
• Exclusive OR
• Spread Operator
• Elvis Operator
• Null Coalescing Operator

Data Format and Types

• PHP Data Types
• PHP Type Juggling
• PHP Type Casting
• PHP strict_types
• Type Hinting
• PHP Boolean Type
• PHP Iterable
• PHP Resource
• Associative Arrays
• Multidimensional Array

Examples: String and Patterns

• Remove the Last Char

Other Tutorials

• require_once & require
• array_map()

• Language Reference

Assignment Operators

The basic assignment operator is "=". Your first inclination might be to think of this as "equal to". Don't. It really means that the left operand gets set to the value of the expression on the right (that is, "gets set to").

The value of an assignment expression is the value assigned. That is, the value of " $a = 3 " is 3. This allows you to do some tricky things: <?php $a = ( $b = 4 ) + 5 ; // $a is equal to 9 now, and $b has been set to 4. ?>

In addition to the basic assignment operator, there are "combined operators" for all of the binary arithmetic , array union and string operators that allow you to use a value in an expression and then set its value to the result of that expression. For example: <?php $a = 3 ; $a += 5 ; // sets $a to 8, as if we had said: $a = $a + 5; $b = "Hello " ; $b .= "There!" ; // sets $b to "Hello There!", just like $b = $b . "There!"; ?>

Note that the assignment copies the original variable to the new one (assignment by value), so changes to one will not affect the other. This may also have relevance if you need to copy something like a large array inside a tight loop.

An exception to the usual assignment by value behaviour within PHP occurs with object s, which are assigned by reference. Objects may be explicitly copied via the clone keyword.

Assignment by Reference

Assignment by reference is also supported, using the " $var = &$othervar; " syntax. Assignment by reference means that both variables end up pointing at the same data, and nothing is copied anywhere.

Example #1 Assigning by reference

The new operator returns a reference automatically, as such assigning the result of new by reference is an error.

The above example will output:

More information on references and their potential uses can be found in the References Explained section of the manual.

Arithmetic Assignment Operators

Bitwise Assignment Operators

Other Assignment Operators

• arithmetic operators
• bitwise operators
• null coalescing operator

Improve This Page

User contributed notes 4 notes.

• How to Concatenate Strings in PHP

Use the Concatenation Operator to Concatenation Strings in PHP

Use the concatenation assignment operator to concatenate strings in php, use the sprintf() function to concatenate strings in php.

This article will introduce different methods to perform string concatenation in PHP.

The process of joining two strings together is called the concatenation process. In PHP, we can achieve this by using the concatenation operator. The concatenation operator is . . The correct syntax to use this operator is as follows.

The details of these variables are as follows.

The program below shows how we can use the concatenation operator to combine two strings.

Likewise, we can use this operator to combine multiple strings.

In PHP, we can also use the concatenation assignment operator to concatenate strings. The concatenation assignment operator is .= . The difference between .= and . is that the concatenation assignment operator .= appends the string on the right side. The correct syntax to use this operator is as follows.

The program below shows how we can use the concatenation assignment operator to combine two strings.

In PHP, we can also use the sprintf() function to concatenate strings. This function gives several formatting patterns to format strings. We can use this formatting to combine two strings. The correct syntax to use this function is as follows.

The function sprintf() accepts N+1 parameters. The detail of its parameters is as follows.

The function returns the formatted string. We will use the format %s %s to combine two strings. The program that combines two strings is as follows:

Related Article - PHP String

• How to Remove All Spaces Out of a String in PHP
• How to Convert DateTime to String in PHP
• How to Convert String to Date and Date-Time in PHP
• How to Convert an Integer Into a String in PHP
• How to Convert an Array to a String in PHP
• How to Convert a String to a Number in PHP

Concatenate Strings in PHP

Php examples tutorial index.

Concatenating strings is a crucial concept in PHP that enables developers to merge two or more strings to create a single string. Understanding how to concatenate strings efficiently is vital in generating dynamic content, creating queries, and managing data output. In this tutorial, you will learn how to concatenate strings in PHP.

Understanding String Concatenation in PHP

String concatenation refers to joining two or more strings to create a new string. It is a typical and helpful operation in PHP, allowing developers to create customized and dynamic strings by combining different sources. The dot ( . ) operator performs this operation in PHP by joining the strings and creating a new string. This feature is simple and efficient and is commonly used in PHP scripting.

Basic Concatenation with the Dot Operator

The easiest and most common way to concatenate strings in PHP is to use the dot ( . ) operator. The dot operator takes two operands (the strings to be concatenated) and returns a new string as the result of concatenating them.

In the above example, we combine two variables ( $firstName and $lastName ) with a space between them to form a full name.

Concatenation with Assignment Operator

PHP makes string manipulation easier with the concatenation assignment operator ( .= ). This operator appends the right-side argument to the left-side argument, making it simple to expand an existing string.

The above method simplifies how to efficiently append text to an existing string variable, enhancing its content without redundancy.

Concatenating Multiple Variables and Strings

You can concatenate multiple variables and strings using multiple dot operators in a single statement. It is beneficial when you need to create a sentence or message from different data sources:

Dynamic Content Creation

String concatenation helps generate dynamic content and allows tailored user experiences based on specific inputs or conditions.

The above example illustrates how to create a personalized greeting message using concatenation dynamically.

In this tutorial, you have learned about the process of string concatenation in PHP, how to use the dot and assignment operators to join strings together, and some examples of string concatenation in PHP for different purposes. String concatenation is a crucial aspect of managing dynamic content and data output. Applying the best practices and techniques outlined in this tutorial, you can efficiently use string concatenation in your PHP projects.

• Interview Problems on String
• Practice String
• MCQs on String
• Tutorial on String
• String Operations
• Sort String
• Substring & Subsequence
• Iterate String
• Reverse String
• Rotate String
• String Concatenation
• Compare Strings
• KMP Algorithm
• Boyer-Moore Algorithm
• Rabin-Karp Algorithm
• Z Algorithm
• String Guide for CP

Concatenation of two strings in PHP

There are two string operators. The first is the concatenation operator (‘ . ‘), which returns the concatenation of its right and left arguments. The second is the concatenating assignment operator (‘ .= ‘), which appends the argument on the right side to the argument on the left side. 

Code #1:  

Time complexity : O(n)  Auxiliary Space : O(n)

  Code #2 : 

  Code #3 :  

  Code #4 :

PHP is a server-side scripting language designed specifically for web development. You can learn PHP from the ground up by following this PHP Tutorial and PHP Examples .

Please Login to comment...

Similar reads.

• Web Technologies
• Best Twitch Extensions for 2024: Top Tools for Viewers and Streamers
• Discord Emojis List 2024: Copy and Paste
• Best Adblockers for Twitch TV: Enjoy Ad-Free Streaming in 2024
• PS4 vs. PS5: Which PlayStation Should You Buy in 2024?
• Full Stack Developer Roadmap [2024 Updated]

Improve your Coding Skills with Practice

What kind of Experience do you want to share?

• PHP Tutorial
• PHP - Introduction
• PHP - Installation
• PHP - History
• PHP - Features
• PHP - Syntax
• PHP - Hello World
• PHP - Comments
• PHP - Variables
• PHP - Echo/Print
• PHP - var_dump
• PHP - $ and $$ Variables
• PHP - Constants
• PHP - Magic Constants
• PHP - Data Types
• PHP - Type Casting
• PHP - Type Juggling
• PHP - Strings
• PHP - Boolean
• PHP - Integers
• PHP - Files & I/O
• PHP - Maths Functions
• PHP - Heredoc & Nowdoc
• PHP - Compound Types
• PHP - File Include
• PHP - Date & Time
• PHP - Scalar Type Declarations
• PHP - Return Type Declarations
• PHP Operators
• PHP - Operators
• PHP - Arithmatic Operators
• PHP - Comparison Operators
• PHP - Logical Operators
• PHP - Assignment Operators
• PHP - String Operators
• PHP - Array Operators
• PHP - Conditional Operators
• PHP - Spread Operator
• PHP - Null Coalescing Operator
• PHP - Spaceship Operator
• PHP Control Statements
• PHP - Decision Making
• PHP - If…Else Statement
• PHP - Switch Statement
• PHP - Loop Types
• PHP - For Loop
• PHP - Foreach Loop
• PHP - While Loop
• PHP - Do…While Loop
• PHP - Break Statement
• PHP - Continue Statement
• PHP - Arrays
• PHP - Indexed Array
• PHP - Associative Array
• PHP - Multidimensional Array
• PHP - Array Functions
• PHP - Constant Arrays
• PHP Functions
• PHP - Functions
• PHP - Function Parameters
• PHP - Call by value
• PHP - Call by Reference
• PHP - Default Arguments
• PHP - Named Arguments
• PHP - Variable Arguments
• PHP - Returning Values
• PHP - Passing Functions
• PHP - Recursive Functions
• PHP - Type Hints
• PHP - Variable Scope
• PHP - Strict Typing
• PHP - Anonymous Functions
• PHP - Arrow Functions
• PHP - Variable Functions
• PHP - Local Variables
• PHP - Global Variables
• PHP Superglobals
• PHP - Superglobals
• PHP - $GLOBALS
• PHP - $_SERVER
• PHP - $_REQUEST
• PHP - $_POST
• PHP - $_GET
• PHP - $_FILES
• PHP - $_ENV
• PHP - $_COOKIE
• PHP - $_SESSION
• PHP File Handling
• PHP - File Handling
• PHP - Open File
• PHP - Read File
• PHP - Write File
• PHP - File Existence
• PHP - Download File
• PHP - Copy File
• PHP - Append File
• PHP - Delete File
• PHP - Handle CSV File
• PHP - File Permissions
• PHP - Create Directory
• PHP - Listing Files
• Object Oriented PHP
• PHP - Object Oriented Programming
• PHP - Classes and Objects
• PHP - Constructor and Destructor
• PHP - Access Modifiers
• PHP - Inheritance
• PHP - Class Constants
• PHP - Abstract Classes
• PHP - Interfaces
• PHP - Traits
• PHP - Static Methods
• PHP - Static Properties
• PHP - Namespaces
• PHP - Object Iteration
• PHP - Encapsulation
• PHP - Final Keyword
• PHP - Overloading
• PHP - Cloning Objects
• PHP - Anonymous Classes
• PHP Web Development
• PHP - Web Concepts
• PHP - Form Handling
• PHP - Form Validation
• PHP - Form Email/URL
• PHP - Complete Form
• PHP - File Inclusion
• PHP - GET & POST
• PHP - File Uploading
• PHP - Cookies
• PHP - Sessions
• PHP - Session Options
• PHP - Sending Emails
• PHP - Sanitize Input
• PHP - Post-Redirect-Get (PRG)
• PHP - Flash Messages
• PHP - AJAX Introduction
• PHP - AJAX Search
• PHP - AJAX XML Parser
• PHP - AJAX Auto Complete Search
• PHP - AJAX RSS Feed Example
• PHP - XML Introduction
• PHP - Simple XML Parser
• PHP - SAX Parser Example
• PHP - DOM Parser Example
• PHP Login Example
• PHP - Login Example
• PHP - Facebook and Paypal Integration
• PHP - Facebook Login
• PHP - Paypal Integration
• PHP - MySQL Login
• PHP Advanced
• PHP - MySQL
• PHP.INI File Configuration
• PHP - Array Destructuring
• PHP - Coding Standard
• PHP - Regular Expression
• PHP - Error Handling
• PHP - Try…Catch
• PHP - Bugs Debugging
• PHP - For C Developers
• PHP - For PERL Developers
• PHP - Frameworks
• PHP - Core PHP vs Frame Works
• PHP - Design Patterns
• PHP - Filters
• PHP - Callbacks
• PHP - Exceptions
• PHP - Special Types
• PHP - Hashing
• PHP - Encryption
• PHP - is_null() Function
• PHP - System Calls
• PHP - HTTP Authentication
• PHP - Swapping Variables
• PHP - Closure::call()
• PHP - Filtered unserialize()
• PHP - IntlChar
• PHP - CSPRNG
• PHP - Expectations
• PHP - Use Statement
• PHP - Integer Division
• PHP - Deprecated Features
• PHP - Removed Extensions & SAPIs
• PHP - FastCGI Process
• PHP - PDO Extension
• PHP - Built-In Functions
• PHP Useful Resources
• PHP - Questions & Answers
• PHP - Quick Guide
• PHP - Useful Resources
• PHP - Discussion
• Selected Reading
• UPSC IAS Exams Notes
• Developer's Best Practices
• Questions and Answers
• Effective Resume Writing
• HR Interview Questions
• Computer Glossary

PHP – String Operators

There are two operators in PHP for working with string data types: concatenation operator (".") and the concatenation assignment operator (".="). Read this chapter to learn how these operators work in PHP.

Concatenation Operator in PHP

The dot operator (".") is PHP's concatenation operator. It joins two string operands (characters of right hand string appended to left hand string) and returns a new string.

The following example shows how you can use the concatenation operator in PHP −

It will produce the following output −

Concatenation Assignment Operator in PHP

PHP also has the ".=" operator which can be termed as the concatenation assignment operator. It updates the string on its left by appending the characters of right hand operand.

The following example uses the concatenation assignment operator. Two string operands are concatenated returning the updated contents of string on the left side −

String Operators in PHP : Tutorial

Concatenation Operator

Concatenation assignment operator (.=).

Primary links

• HTML Color Chart
• Knowledge Base
• Devguru Resume
• Testimonials
• Privacy Policy

Font-size: A A A

PHP » Operators » .=

Concatenation assignment operator.

Concatenates the left operand and the right operand.

Explanation:

A variable is changed with an assignment operator.

© Copyright 1999-2018 by Infinite Software Solutions, Inc. All rights reserved.

Trademark Information | Privacy Policy

Event Management Software and Association Management Software

• ▼PHP Operators
• Arithmetic Operators
• Comparison Operators
• Logical Operators
• Assignment Operators
• Bitwise Operators

String Operators

• Array Operators
• Incrementing Decrementing Operators

PHP: String operator

There are two string operators : concatenation operator ('.') and concatenating assignment operator ('.=').

Example : PHP string concatenation operator

View the example in the browser

Example: PHP string concatenating assignment operator

View the example of in the browser

Previous: Bitwise Operators Next: Array Operators

Follow us on Facebook and Twitter for latest update.

• Weekly Trends and Language Statistics

PHP Tutorial

Php advanced, mysql database, php examples, php reference, php operators.

Operators are used to perform operations on variables and values.

PHP divides the operators in the following groups:

• Arithmetic operators
• Assignment operators
• Comparison operators
• Increment/Decrement operators
• Logical operators
• String operators
• Array operators
• Conditional assignment operators

PHP Arithmetic Operators

The PHP arithmetic operators are used with numeric values to perform common arithmetical operations, such as addition, subtraction, multiplication etc.

PHP Assignment Operators

The PHP assignment operators are used with numeric values to write a value to a variable.

The basic assignment operator in PHP is "=". It means that the left operand gets set to the value of the assignment expression on the right.

Advertisement

PHP Comparison Operators

The PHP comparison operators are used to compare two values (number or string):

PHP Increment / Decrement Operators

The PHP increment operators are used to increment a variable's value.

The PHP decrement operators are used to decrement a variable's value.

PHP Logical Operators

The PHP logical operators are used to combine conditional statements.

PHP String Operators

PHP has two operators that are specially designed for strings.

PHP Array Operators

The PHP array operators are used to compare arrays.

PHP Conditional Assignment Operators

The PHP conditional assignment operators are used to set a value depending on conditions:

COLOR PICKER

Contact Sales

If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail: [email protected]

Report Error

If you want to report an error, or if you want to make a suggestion, send us an e-mail: [email protected]

Top Tutorials

Top references, top examples, get certified.

• Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers
• Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand
• OverflowAI GenAI features for Teams
• OverflowAPI Train & fine-tune LLMs
• Labs The future of collective knowledge sharing
• About the company Visit the blog

Collectives™ on Stack Overflow

Find centralized, trusted content and collaborate around the technologies you use most.

Q&A for work

Connect and share knowledge within a single location that is structured and easy to search.

Get early access and see previews of new features.

Concatante PHP variables inside loop by a "Concatenating Assignment Operator", and Echo each output loop separately

With the "Concatenating Assignment Operator" I assigned in the loop two variables. I need to get each loop result separately. The problem is that I don't know why each next loop result is copied to each next loop result.

Using this code, I get the output:

I'm working on making the output look like this:

• 7 You need to reset $output at the top of the loop. –  aynber Commented Dec 1, 2021 at 14:14

You are always concatenating values to the $output, you never clear it, so the numbers are just continually added. All you need to do is change the first $output .= "1"; in to a $output = "1"; and that will have the effect of resetting $output to the one character ready to be concatenated with the second.

Your Answer

Reminder: Answers generated by artificial intelligence tools are not allowed on Stack Overflow. Learn more

Sign up or log in

Post as a guest.

Required, but never shown

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy .

Not the answer you're looking for? Browse other questions tagged php arrays while-loop or ask your own question .

• The Overflow Blog
• The evolution of full stack engineers
• One of the best ways to get value for AI coding tools: generating tests
• Featured on Meta
• User activation: Learnings and opportunities
• Site maintenance - Mon, Sept 16 2024, 21:00 UTC to Tue, Sept 17 2024, 2:00...
• Staging Ground Reviewer Motivation
• What does a new user need in a homepage experience on Stack Overflow?

Hot Network Questions

• Is there mathematical significance to the LaGuardia floor tiles?
• Engaging students in the beauty of mathematics
• Can a V22 Osprey operate with only one propeller?
• Why are my empty files not being assigned the correct mimetype?
• Does hydrogen peroxide work as a rocket fuel oxidizer by itself?
• Seeking Advice for Outdoor Junction Box
• "Truth Function" v.s. "Truth-Functional"
• When does a finite group have finitely many indecomposable representations?
• How do I go about writing a tragic ending in a story while making it overall satisfying to the reader?
• BASH - Find file with regex - Non-recursively delete number-only filenames in directory
• Word switching from plural to singular when it is many?
• Why does friendship seem transitive with befriended function templates?
• What does the phrase 'sons of God'/בני אלוהים mean throughout the Hebrew bible?
• Book that features clones used for retirement
• MSSQL - query runs for too long when filtering after a certain date
• If a friend hands me a marijuana edible then dies of a heart attack am I guilty of felony murder?
• Is this a misstatement of Euclid in Halmos' Naive Set Theory book?
• How can a microcontroller (such as an Arduino Uno) that requires 7-21V input voltage be powered via USB-B which can only run 5V?
• Paying a parking fine when I don't trust the recipient
• Inequality involving finite number of nonnegative real numbers
• What are the pros and cons of the classic portfolio by Wealthfront?
• Big Transition of Binary Counting in perspective of IEEE754 floating point
• Is Produce Flame a spell that the caster casts upon themself?
• jq - ip addr show in tabular format