What is the use of concatenation in php?

String concatenation is a very common and useful operation in PHP. There are many ways in which you might want to join strings together like prepending, appending, or combining them at some other point.

In this quick tip, I'll teach you string concatenation in PHP. You'll learn how to prepend or append strings in PHP and how to concatenate strings together at specific positions.

Prepend and Append Strings in PHP

Concatenating strings in PHP by either appending or prepending is actually pretty simple. There are two string operators in PHP meant for this specific purpose.

You can use the concatenation operator . if you want to join strings and assign the result to a third variable or output it. This is useful for both appending and prepending strings depending on their position.
You can use the concatenating assignment operator .= if you want to join the strings and assign the result to the same variable. It is a shorter way of appending the argument on the right side to the argument on the left side.

Here is an example which shows how to append strings in PHP:

Here is an example that prepends different strings to a name in PHP:

Concatenating Strings at a Particular Point

There are two common cases when you need to join strings at some place other than the beginning or the end of a string. These are splitting the main string at a particular index, or splitting the main string after a particular word. We will cover both these situations in this section.

Concatenating Strings at a Particular Index

We can use the substr[] function in PHP to split the main string in two parts at the desired index and then join the parts back together with our string in the middle.

In the above code, the value of the $index variable is simply the position at which we would like to concatenate our substring inside the main string.

Concatenating Strings Before or After a Particular Word

Concatenating a string before or after a particular word works just like joining strings at a particular index. The only extra step we need to take is to figure out the index. The strpos[$haystack, $needle] function is perfect for this purpose. It simply finds the position of our $needle string inside the main text block or $haystack.

Here is an example of concatenating strings before a particular word.

The big difference here is that we have moved the $index variable inside our loop. This is because the position of our word will probably be different in each string, and we need to adjust the value of the index accordingly.

The strpos[] function gives us the position of the first character of our substring inside the main string. This makes it easier for us to concatenate the substring at the beginning of a particular word.

When adding substrings at the end of words, we also need to take the length of words into account. Adding the word length to our initial index gives us the correct position to concatenate the substring at the end of a particular word.

Final Thoughts

In this quick tip, I have covered different scenarios for concatenating strings in PHP. You should now be able to append, prepend, or join the strings at any other position you like.

The key to joining the strings at a particular place is to simply find the index. This is exactly what we did when we wanted to concatenate strings before or after a particular word.

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I am a full-stack developer who also loves to write tutorials. After trying out a bunch of things till second year of college, I decided to work on my web development skills. Starting with just HTML and CSS, I kept moving forward and gained experience in PHP, JavaScript and Python. I usually spend my free time either working on some side projects or traveling around.

Why we use concatenate in PHP?

Prepend and Append Strings in PHP You can use the concatenation operator . if you want to join strings and assign the result to a third variable or output it. This is useful for both appending and prepending strings depending on their position. You can use the concatenating assignment operator .

What is used for concatenation?

The ampersand symbol is the recommended concatenation operator. It is used to bind a number of string variables together, creating one string from two or more individual strings.

What is the concatenation operator used for?

The concatenation operator is a binary operator, whose syntax is shown in the general diagram for an SQL Expression. You can use the concatenation operator [ || ] to concatenate two expressions that evaluate to character data types or to numeric data types.

What is the use of string concatenation?

Concatenation is the process of appending one string to the end of another string. You concatenate strings by using the + operator. For string literals and string constants, concatenation occurs at compile time; no run-time concatenation occurs. For string variables, concatenation occurs only at run time.