A string variable is used to store
and manipulate a piece of text.
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.
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.
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)
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.
For a complete reference of all
string functions, go to our complete PHP String
Reference.
The reference contains a brief
description and examples of use for each function!