972781
Description
Flashcards by Nathan Hunsdale, updated more than 1 year ago
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Created by Nathan Hunsdale
almost 10 years ago
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| Question | Answer |
| Variables What are they? | They are named locations which refer to data stored on the system's memory |
| Java distinguishes between 2 types of data: What are they? | 1) Primitive data types 2) Instances of classes (OBJECTS) |
| Variables To be able to use variables they need to be _____ | declared |
| Variables The first thing to happen in a program is usually _____ variables | declaring |
| Variables Choosing a suitable name The names given to a variable are known as an _____ | identifier |
| Variables Identifiers - Cannot START with a _____ - Cannot use _____ or spaces - Should start with _____ _____ names | - Cannot START with a number - Cannot use symbols or spaces - Should start with LOWER CASE names |
| Primitive Data Types How many are there? | 8 |
| Primitive Data Types Every _____ must have a type associated with it | variable |
| Primitive Data Types What are the 8? | - byte - short - int - long - float - double - char - boolean |
| Primitive Data Types byte Minimum value : _____ Max value : _____ Default Value : _____ It is used to _____ _____ in large arrays as they are 4 times smaller than ints | Minimum value : -128 Max value : 127 Default Value : 0 It is used to SAVE SPACE in large arrays as they are 4 times smaller than ints |
| Primitive Data Types short Number of bits : _____ Default Value : _____ It is used to _____ _____ in large arrays as they are _____ times smaller than ints | Number of bits : 16 Default Value : 0 It is used to SAVE SPACE in large arrays as they are 2 times smaller than ints |
| Primitive Data Types int Number of bits : _____ Default Value : _____ Generally used as the default data type for integral values unless there is a concern about _____ | Number of bits : 32 Default Value : 0 Generally used as the default data type for integral values unless there is a concern about SPACE |
| Primitive Data Types long Number of bits : _____ Default Value : _____ Used when a wider range than an _____ is needed | Number of bits : 64 Default Value : 0 Used when a wider range than an int is needed |
| Primitive Data Types float Number of bits : _____ Default Value : _____ Used to save memory in large arrays of _____ _____ numbers It is never used for _____ values such as currency | Number of bits : 32 Default Value : 0.0 Used to save memory in large arrays of FLOATING POINT numbers It is never used for PRECISE values such as currency |
| Primitive Data Types double Number of bits : _____ Default Value : _____ Used as the default data type for _____ values It is never used for _____ values such as currency | Number of bits : 64 Default Value : 0.0 Used as the default data type for DECIMAL values It is never used for PRECISE values such as currency |
| Primitive Data Types boolean Default Value : _____ Used as the default data type to track _____ or _____ | Default Value : false Used as the default data type to track TRUE or FALSE |
| Primitive Data Types char Number of bits : _____ Used to store _____ character | Number of bits : 16 Used to store any character |
| Reference Data Types Reference variables are created using defined _____ of the classes | constructors |
| Reference Data Types They are used to access _____ | Reference Data Types They are used to access OBJECTS |
| Reference Data Types They include _____ and _____ _____ | They include variables and class objects |
| Variables Declare an int called number | int number; |
| Variables Initialize an int called number with a value of 4 | number = 4; |
| Variables What symbol is the assignment operator when assigning values to variables? | = |
| Variables What is an expression? | A portion of code containing calculations |
| Relational Operators What is a condition? | An expression that can be true or false |
| Relational Operators What does an if statement allow a program to do? | Make a decision based on a condition's value |
| Under the Bonnet JVM What does it stand for? | Java Virtual Machine |
| Under the Bonnet JVM Is it platform independent? | Yes |
| Under the Bonnet One major advantage and characteristic of Java is _____ | Portability |
| Portability How is it achieved? What is the intermediary between the Java language and the OS? | Java Bytecode |
| Java Bytecode How is it executed? | The JVM is tailored to the hardware of the specific computer but the bytecode runs on the JVM, so it is independent of the physical machine |
| Compiling and Running What is the file extension for a Java file? | .java |
| What is used to turn the source code into bytecode? | Javac |
| After Javac finishes compiling the source code then it creates a new class with the extension _____ | .class |
| Which file extension does the JVM run? | .class |
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