Cleaning Strings

Often, the strings we get from files or users need to be cleaned up before we can use
them. Two common problems with raw data are the presence of extraneous
whitespace, and incorrect capitalization (uppercase versus lowercase).

Removing Whitespace

You can remove leading or trailing whitespace with the trim( ), ltrim( ), and rtrim( )
functions:
$trimmed = trim(string [, charlist ]);
$trimmed = ltrim(string [, charlist ]);
$trimmed = rtrim(string [, charlist ]);

trim( ) returns a copy of string with whitespace removed from the beginning and
the end. ltrim( ) (the l is for left) does the same, but removes whitespace only from
the start of the string. rtrim( ) (the r is for right) removes whitespace only from the
end of the string. The optional charlist argument is a string that specifies all the
characters to strip.

For example:
$title = " Programming PHP \n";
$str_1 = ltrim($title); // $str_1 is "Programming PHP \n"
$str_2 = rtrim($title); // $str_2 is " Programming PHP"
$str_3 = trim($title); // $str_3 is "Programming PHP"