Strings in PHP

String variables are used for values that contains character strings.In this tutorial we are going to look at some of the most common functions and operators used to manipulate strings in PHP.
After we create a string we can manipulate it. A string can be used directly in a function or it can be stored in a variable.
Below, the PHP script assigns the string "Hello World" to a string variable called $txt:

<?php
$txt="Hello World";
echo $txt;
?>

The output of the code above will be:

Hello World

Now, lets try to use some different functions and operators to manipulate our string.

The Concatenation Operator

There is only one string operator in PHP.
The concatenation operator (.)  is used to put two string values together.
To concatenate two variables together, use the dot (.) operator:

<?php
$txt1="Hello World";
$txt2="1234";
echo $txt1 . " " . $txt2;
?>

The output of the code above will be:

Hello World 1234

If we look at the code above you see that we used the concatenation operator two times. This is because we had to insert a third string.
Between the two string variables we added a string with a single character, an empty space, to separate the two variables.

Using the strlen() function

The strlen() function is used to find the length of a string.
Let's find the length of our string "Hello world!":

<?php
echo strlen("Hello world!");
?>

The output of the code above will be:

12

The length of a string is often used in loops or other functions, when it is important to know when the string ends. (i.e. in a loop, we would want to stop the loop after the last character in the string)

Using the strpos() function

The strpos() function is used to search for a string or character within a string.
If a match is found in the string, this function will return the position of the first match. If no match is found, it will return FALSE.
Let's see if we can find the string "world" in our string:

<?php
echo strpos("Hello world!","world");
?>

The output of the code above will be:

6

As you see the position of the string "world" in our string is position 6. The reason that it is 6, and not 7, is that the first position in the string is 0, and not 1.
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