38. The unset function can be used to destroy a variable. Answer: D.
39. The "a" mode of the fopen() function opens a file for writing and places the file pointer at the end of the file. Answer: B.
40. The HTTP_USER_AGENT HTTP variable contains the browser type, and browser version, among other values. Answer: D.
41. This operation subtracts 150 from the existing value. Answer: C.
42. Parentheses are used to enclose conditional expressions. Answer: B.
43. The Boolean PHP data type can be either TRUE or FALSE. Answer: C.
44. $_FILES contains variables provided to a script by means of file uploads. Answer: A.
45. The RAND_MAX constant identifies the highest random number that a system can generate. Answer: D.
46. PHP provides support for POSIX through functions of the ereg class. Answer: B.
47. From a Boolean standpoint, every zero value in PHP is considered false. Answer: B.
48. The arsort() function places results in the opposite order of asort(). Answer: A.
49. The printf type specifier s is used for a string. Answer: C.
50. The != PHP conditional operator means not equal to. Answer: A.
Emmett Dulaney is the author of the several books on Linux/Unix and certification as well as a columnist for UnixReview.com. Emmett's blog can be found at: http://edulaney.blogspot.com, and he can be reached (and welcomes your comments) at: edulaney@insightbb.com.
