wiki - Benutzerbeiträge [de-ch]

Glossary

2016-11-28T23:01:30Z

Susi: Die Seite wurde neu angelegt: « key | description primitive variables | such as int, bool, double -> copy by value Wrapper class | such as Boolean, Double, Integer»

key | description

primitive variables | such as int, bool, double -> copy by value
Wrapper class | such as Boolean, Double, Integer

Chapter 1

2016-11-28T22:59:08Z

Susi: Die Seite wurde neu angelegt: «= Chapter 1 = ==Objectives== === Java Basics === * Define the scope of variables * Define the structure of a Java class * Create executable Java applications, Ru…»

= Chapter 1 =
==Objectives==
=== Java Basics ===
* Define the scope of variables
* Define the structure of a Java class
* Create executable Java applications, Run a Java program from command line
* Import other Java packages
* Compare and contrast features and components of Java
=== Working with Java Data Types===
* Declare and initialize variables
* Difference between object reference variables and primitive variables
* know how to read and write to object fields
* explain an objects lifecycle
(creation, "dereference by reassignment", garbage collection)
* develop code that uses wrapper classes
(Boolean, Double, Integer)

==scopes==
==structure==
Java classes have two primary elements: methods and fields.
* fields/variables: hold a state of the program
* methods: operate on the state

1 file = 1 class, if you have two classes, 1 must bi public an match the filename, other class can be private but not public too

classes are logical grouped into packages

if package starts with java or javax, this means it came with the JDK
packages names are mostly letters and numbers separated by dots.

wildcards for matching all classes in the same package
(not every class in the package is imported, the compiler figures out what's actually needed)

a wildcard only matches class names, not "fie.Files* -> import java.nio.*; not possbile
only one wildcard is possible in an import-statement

package java.lang is automatically imported, you can type this package as an import statement, but you don't have to

default package, is a special unnamed package that you should use only for throwaway code

java looks in the current package for other classes.

==compare and contrast features and components==
==declare and initialize variables==
==object variables vs. primitive variables==
==read and write object fields==
==object lifecycle==
==wrapper classes==
==imports==

===main method===
String[] args, String args[], String ... args
are all correct

Oracle Certified

2016-11-28T22:55:56Z

Susi: /* Sites */

Prepare the exam

2016-11-28T22:54:59Z

Susi: Die Seite wurde neu angelegt: «= Prepare the Exam = == common tips to determine if code compiles == * Keep an eye out for all reserved words Chapter 1 * Verify brackets - {} - and parenth…»

= Prepare the Exam =

== common tips to determine if code compiles ==
* Keep an eye out for all reserved words [[Chapter 1]]
* Verify brackets - {} - and parentheses-()- are being used correctly.[[Chapter 1]]
* Verify new is used appropriately for creating objects [[Chapter 1]]
* Ignore all line indentation especially with if-then statements that do not use brackters[]. [[Chapter 2]]
* Make sure operators use compatible data types, such as the logical complement operator(!) only applied to boolean values, and arithmetic operators (+,-,++,--) only applied to numeric values [[Chapter 2]]
* For any numeric operators, check for autimatic numeric promotion and order or operation when evaluating an expression [[Chapter 2]]
* Verify switch statements use acceptable data types [[Chapter 2]]
* Remember == is not the same as equals(). [[Chapter 3]]
* String values are immutable [[Chapter 3]]
* Non-void methods must return a value that matches or is a subclass of the return type ot the method [[Chapter 4]]
* If two classes are involved, make sure access modifies allow proper access of variables and methods [[Chapter 4]]
* Nonstatic methods and variables require an object instance to access [[Chapter 4]]
* If a class is missing a default no-argument constructor or the provided constructors do not explicitly call super(), assume the compiler will automatically insert them [[Chapter 5]]
* Make sure abstract methods do not define an implementation, and likewise concrete methods always define an implementation [[Chapter 5]]
* You implement an interface and extend a class [[Chapter 5]]
* A class can be cast to a reference of any superclass it inherits from or interface its implements [[Chapter 5]]
* Checked exceptions must be caught, unchecked exceptions may be caught but do not nedd to be [[Chapter 6]]
* try blocks require a catch and/or finally block for the OCA exam [[Chapter 6]]
== Tips during taking the test ==
* Answer all Questions-> Guess an answer
* Understand relationship between answers
* check for answers do not compile due to line x
* have a look at the starting linenumber, maybe includes are needed for complie, if it starts with 1...
* skip hard questions and mark it for "review"
== Optimizing your time ==

* 120 min remaining start the exam
* 90 min remaining 1/3 finished
* 60 min remaining 2/3 finished
* 30 min remaining fist pass pf all questions complete
* 5 min finished questions which were marked for "review"

(for example 2h and 90 questions)

Oracle Certified

2016-11-28T22:50:05Z

Susi: Die Seite wurde neu angelegt: « == Sites == * prepare the exam * chapter1 * chapter2 * chapter3 * chapter4 * chapter5 * chapter6 * glossary == Exam Objectives…»