String Variables

A string variable is used to store and manipulate text.

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String Variables in PHP

String variables are used for values that contain characters.

In this chapter we are going to look at 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 text "Hello World" to a string variable called $txt:

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

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 string variables together, use the concatenation operator:

<?php $txt1="Hello World!"; $txt2="What a nice day!"; echo $txt1 . " " . $txt2; ?>

The output of the code above will be:

Hello World! What a nice day!

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 (a space character), to separate the two strings.

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The strlen() function

The strlen() function is used to return the length of a string.
Let's find the length of a string:

<?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).

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The strpos() function

The strpos() function is used to search for character within a string.
If a match is found, 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

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.