سؤال بس مش تحدي

[php]السلاااااااااااااام عليكم ورحمة الله و بركاته
هذه اسئله لمن يحب ان يجيب عليها 
و لكنها ليست اسئلة تحدي


Find The errors.

a) While ( c<= 5)
{
product *= c;
++c;

//-----------------------------------------------

b)In order for the following code to be correct, what must be the type of the reference variable card? 
_________ card;

card = new Valentine( "Joe", 14 ) ;
card.greeting();

card = new Holiday( "Bob" ) ; 
card.greeting();

card = new Birthday( "Emily", 12 ) ; 
card.greeting();

//-------------------------------------------------

c)The following code will print the values ........ 

n = 1; 
while(n < 10) { 
System.out.print(n++); 
if(n == 5) 
continue; 
}

//--------------------------------------------------