PHP interview question answers

• What’s the difference between include and require?
  – 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.
• I am trying to assign a variable the value of 0123, but it keeps coming up with a different number, what’s the problem?
  - PHP Interpreter treats numbers beginning with 0 as octal.
• Would I use print “$a dollars” or “{$a} dollars” to print out the amount of dollars in this example? – In this example it wouldn’t matter, since the variable is all by itself, but if you were to print something like “{$a},000,000 mln dollars”, then you definitely need to use the braces.
• How do you define a constant?
  - Via define() directive, like define (“MYCONSTANT”, 100);
• How do you pass a variable by value?
  - Just like in C++, put an ampersand in front of it, like $a = &$b
• Will comparison of string “10″ and integer 11 work in PHP?
  - Yes, internally PHP will cast everything to the integer type, so numbers 10 and 11 will be compared.
• When are you supposed to use endif to end the conditional statement?
  - When the original if was followed by : and then the code block without braces.
• Explain the ternary conditional operator in PHP?
  - Expression preceding the ? is evaluated, if it’s true, then the expression preceding the : is executed, otherwise, the expression following : is executed.
• How do I find out the number of parameters passed into function?
  - func_num_args() function returns the number of parameters passed in.
• If the variable $a is equal to 5 and variable $b is equal to character a, what’s the value of $$b?
  - 100, it’s a reference to existing variable.