After studying the variables, we continued the discussion of the trim and strlen function. The second function is used to manipulate the string.
- Trim (); used to remove the spaces on the right or left a text, examples of program code is as follows:

< ? php
$text=" test trim ";
$text=trim($text);
echo $text.$text;
?>

< ? php
$text1=" test trim ";
$text2=trim($text1);
$lentext1=" Text1 Length = ".strlen($text1);
$lentext1=" Text2 Length = ".strlen($text2);
echo $lentext2."
";
echo $lentext1;
?>

In making a program, it should not be forgotten is variable. Variable plays an important role in the process of temporary data storage. Writing variables should also be noted. In writing PHP variables are always denoted by sign ($) in front of variable names. Variable names must consist of one syllable, could also be a combination of numbers with letters, but should not be preceded by the numbers.
Example:
$ NumBook = 23;

Note:
PHP is case sensitive, which means writing small and large very influential. To facilitate the writing of program code, it's worth all the code is written in small letters.

To print the value of a variable can be done in the following ways:
$ Number = 23;
echo $ number

Rules in the PHP code, beginning with a <?php and ends with the sign ?> block PHP always flanked by a second sign. For each command will end with a sign; (semicolon). The following example PHP code.

< ? php
echo "Hello World";
? >