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: 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
5. What?s the difference between md5( ), crc32( ) and sha1( ) crypto on PHP?
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
6. How do you call a constructor for a parent class?
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
8. For printing out strings, there are echo, print and printf. Explain the differences.
Correct Answer: - echo is the most primitive of them, and just outputs the contents following the construct to the screen print is also a construct (so parentheses are optional when calling it), but it returns TRUE on successful output and FALSE if it was unable to print out the string However, you can pass multiple parameters to echo, like: and it will output the string "Welcome to TechInterviews!" print does not take multiple parameters It is also generally argued that echo is faster, but usually the speed advantage is negligible, and might not be there for future versions of PHP printf is a function, not a construct, and allows such advantages as formatted output, but it?s the slowest way to print out data out of echo, print and printf
9. What?s the difference between htmlentities( ) and htmlspecialchars( )?
Correct Answer: htmlspecialchars only takes care of , single quote ?, double quote " and ampersand htmlentities translates all occurrences of character sequences that have different meaning in HTML