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Learning PHP, MySQL, and JavaScript by Robin Nixon

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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 as printf("%'*7.5s", "Happy Birthday");.

Question 7-3

To send the output from printf to a variable instead of to a browser, you would use sprintf 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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