Java Final

How many primitive types of java are there?

8: Int, double, char, float, boolean, byte, long, short

Arrays in java are: A. Object references B. Object C. Primitive type D. None

A

int [ ] B = {0,2,4,1,3} for ( int i = 0; i <a.length; i++){ b[i] = b[(b[i]+3) % b.length];} For b[1] A. 0 B. 1 C. 2 D. 3

A

What are in packages?

A collection of classes and interfaces

Class

A collection of data that provides a set of methods; a factory for creating objects

When an array is passed to a method, what does the method receive? A. The reference of the array B. Copy of the first element C. Copy of the array D. Length of the array

A; the reference of the array

Constructor

Allocate memory for objects and initialize data fields

What is the correct way to create an object?

Animal cat = new Animal(); Animal dog = new Animal();

When is the object created with a new keyword?

At run time

Which keyword is used to import a package from the java API Library? A. Package B. Import C. Class D. Getlib

B

Which index is the last element in an array called numbs at? A. numbs. length; B. numbs.length-1;

B; arrays start at 0 not 1

Which of the following are correct? A. String [ ] str = new String (10); B. String [ ] str = new String [1]; C. String [ ] str = new String (); D. String [ ] str = new String [];

B; declare size of array

What is a package?

Class and interface

Object

Collection of data; needs attribute and a class, performs actions

Diamond

Condition

private int [ ] b = {1,3,-5,-2} public void mult ( int a ){ int i = 0 a = 3 while ( i < b.length){ b[i] = b[i]*a;}} A. {1,3,-5,-2} B. {3,9,-15,-6} C. {2,6,-10,-4} D. The code will never stop executing due to an infinite loop

D; there is no incrementation I, or the answer is b if there is an i++ added

public static double mystery (int [ ] val) { Int [ ] val = {10,30,30,60} double sum = 0 for ( int i = 0; i < val.length; i++) { sum = sum + val [i]} Return sum/val.length}} A. 17.5 B. 30.0 C. 130 D. 32 E. 32.5

E; get the mean of the numbers

Where are constructors?

Inside the parentheses: Animal cat = new Animal(age, name);

What is the implicit return type of a constructor?

No return type

m = 0

Start

Rectangle

Statement

m = m + 1

True side

UML

Unified Modeling Language