How to check if a variable is empty?

Which code snippet would give two functions that would take a string and return, if it starts or ends with the specified character/string? For example: $str='|apples}'; echo startsWith($str,'|'); //Returns true echo endsWith($str,'}'); //Returns true

Which will produce a value of '83' as its output??

Which is not a valid directive for declare construct?

Time interval in the given dateInterval object specification: new DateInterval('P0000-10-00T00:01:01');

Which PHP sort method sorts by value?

$var = (10 % 2 == 0) ? true:false; What is the output of $var?

Which PHP function opens a file for reading only?

Which are examples of PHP comments?

Which does not represent a single, valid PHP variable

Which statements start a session and end a session?