Give the output of the following code:

String P = "20", Q ="19";
int a = Integer.parseInt(P);
int b = Integer.valueOf(Q);
System.out.println(a+""+b);

String s1 = "45.50"; String s2 = "54.50";
double d1=Double.parseDouble(s1);
double d2=Double.parseDouble(s2);
int x= (int)(d1+d2);

What is value of x?

The method to convert a String to double is:

1. String.toDouble()
2. Double.Parsedouble()
3. Double.parseDouble(String)
4. Double.parseDouble()