Learning PHP, MySQL, JavaScript, and CSS, 2nd Edition

Chapter 7 Answers

1. The conversion specifier you would use to display a floating-point number is %f.

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");.

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

4. To create a Unix timestamp for 7:11 AM on May 2, 2016, you could use the command $timestamp = mktime(7, 11, 0, 5, 2, 2016);.

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.

6. The PHP command for deleting the file file.txt is unlink('file.txt');.

7. The PHP function file_get_contents is used to read in an entire file in one go. It will also read a file from across the Internet if provided with a URL.

8. The PHP associative array $_FILES contains the details about uploaded files.

9. The PHP exec function enables the running of system commands.

10. In XHTML 1.0, the tag <input type=file name=file size=10> should be replaced with the following syntax: <input type="file" name="file" size="10" />. All parameters must be quoted, and tags without closing tags must be self-closed using />.