Java Certification 1 (2025)

For very large numbers with decimals, which data type should be used?

• Float

• Short

• Double

• Boolean

• Long

Where does a java program start executing instructions from:

• class

• source file

• main method

• object

Using the dropdown menus, finish the following code so that the first print prints the number of characters in the s1 variable. The second print needs to print the hexadecimal version of s1.

public class Main {
  public static void main(String[] args) {
    String s1 = "bookworm reader";

int i1 =s1. (a)   ;

 System.out.println(i1);

String s2 = ​ (b)   ("​ (c)   ", i1);​

System.out.println(s2);

}

}

• length
• length();
• %x
• String.format
• String.convert
• %h
• %e

Which is not a compound assignment operator?

• *=

• /=

• =

• -=

Which of the following statements about instance variables is true?

• They are accessible only inside the method where they are declared.

• They are shared across all instances of a class.

• They are accessible anywhere inside the class but belong to an instance of the class.

• They cannot have different values for different objects.

A new Java developer is trying to get a better understanding of how unary operators affect variables and their displayed values. Using drag and drop, match each print statement with its correct answer, using the following variable declarations:

int x = 13;

int y = 3;

​ ​​ (a)   3

​ (b)   ​ 14​ ​

​ (c)   ​ 12

​ (d)   13

• System.out.println(y--);
• System.out.println(++x);
• System.out.println(x-=1)
• System.out.println(x++);

What will be the output of this code?

String s="Stacey";

s.concat(" Green");

System.out.println(s);

s = "Robin Little";

• Robin Little

• Stacey Green

• Stacey

• Green

Please indicate if the following statement is true or false:

A .java file can only have one public, non-static class

• True

• False

Please indicate if the following statement is true or false:

A .java file can only have one class

• True

• False

A(n) _______ member uses one memory space, no matter how many times it is called.

• static

• instance