Chapter 7 Answers
- Question 7-1
The conversion specifier you would use to display a floating-point number is
%f
.- Question 7-2
To take the input string “Happy Birthday” and output the string “**Happy”, you could use a
printf
statement such asprintf("%'*7.5s", "Happy Birthday");
.- Question 7-3
To send the output from
printf
to a variable instead of to a browser, you would usesprintf
instead.- Question 7-4
To create a Unix timestamp for 7:11am on May 2nd 2016, you could use the command
$timestamp = mktime(7, 11, 0, 5, 2, 2016);
.- Question 7-5
You would use the “w+” file access mode with
fopen
to open a file in write and read mode, with the file truncated and the file pointer at the start.- Question 7-6
The PHP command for deleting the file file.txt is
unlink('file.txt');
.- Question 7-7
The PHP function
file_get_contents
is used to read in an entire file in one go. It will also read them from across the Internet if provided with a URL.- Question 7-8
The PHP associative array
$_FILES
contains the details about uploaded files.- Question 7-9
The PHP
exec
function enables the running of system commands.- Question 7-10
In XHTML 1.0, the tag
<input type=file name=file size=10>
should be replaced with the following correct syntax<input type="file" name="file" size="10" />
, because all parameters must be quoted, and tags without closing tags must be self closed using/>
.
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