How do you define a constant?

Correct Answer: It?s how they handle failures If the file is not found by require(), it will cause a fatal error and halt the execution of the script If the file is not found by include(), a warning will be issued, but execution will continue

Correct Answer: The major difference is the length of the hash generated CRC32 is, evidently, 32 bits, while sha1() returns a 128 bit value, and md5() returns a 160 bit value This is important when avoiding collisions

Correct Answer: The first one is octal 23, the second is hex 23

Correct Answer: __sleep returns the array of all the variables than need to be saved, while __wakeup retrieves them

Correct Answer: 100, it?s a reference to existing variable

Correct Answer: Just like in C++, put an ampersand in front of it, like $a = &$b

Correct Answer: Expression preceding the ? is evaluated, if it?s true, then the expression preceding the : is executed, otherwise, the expression following : is executed

Correct Answer: Everything is passed by value

Correct Answer: parent::constructor($value)

Correct Answer: Since the data inside the single-quoted string is not parsed for variable substitution, it?s always a better idea speed-wise to initialize a string with single quotes, unless you specifically need variable substitution