PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

Formatting Strings
113
Table 4.1
Type
s
u
x
X
Continued
Meaning
Interpret as a string and print as a string.
Interpret as an integer and print as an unsigned decimal.
Interpret as an integer and print as a hexadecimal number with lowercase letters for
the digits a–f.
Interpret as an integer and print as a hexadecimal number with uppercase letters for
the digits A–F.
When using the printf() function with conversion type codes, you can use argument
numbering.That means that the arguments don’t need to be in the same order as the
conversion specifications. For example,
printf (“Total amount of order is %2\$.2f (with shipping %1\$.2f) “,
$total_shipping, $total);
Just add the argument position in the list directly after the % sign, followed by an escaped
$ symbol; in this example, 2\$ means “replace with the second argument in the list.”This
method can also be used to repeat arguments.
Two alternative versions of these functions are called vprintf() and vsprintf().
These variants accept two parameters: the format string and an array of the arguments
rather than a variable number of parameters.
Changing the Case of a String
You can also reformat the case of a string.This capability is not particularly useful for the
sample application, but we’ll look at some brief examples.
If you start with the subject string, $subject, which you are using for email, you can
change its case by using several functions.The effect of these functions is summarized in
Table 4.2.The first column shows the function name, the second describes its effect, the
third shows how it would be applied to the string $subject, and the last column shows
what value would be returned from the function.
Table 4.2 String Case Functions and Their Effects
Function Description Use Value
$subject
Feedback from
web site
strtoupper() Turns string to strtoupper($subject) FEEDBACK
uppercase
FROM
WEB SITE
strtolower() Turns string to strtolower($subject) feedback from
lowercase
web site
ucfirst() Capitalizes first ucfirst($subject) Feedback from
character of string
web site
if it’s alphabetic