what makes java portable and archtecture neutral?

this has been mproved in java due to the recent introduction of

in the case of loops, the statment within a loop must be interpreted each time around the loop

code executed immediately after editing, no compilation step in between

execution time is increased since each line must be interpreted each time the program is executed

optional, in the case of c/c++, turns source code into preprocessed source code

program structure determined by #include statements

filenames in java must match their class name(including capitalization), in c++ thats just a suggestion for the header/imp filenames

java class Foo will have its source code stored in
and its compiled code stored in

package named Baz, containing classes Foo and Bar will have their source and compiled code stored in

in java object code is stored in a .class file as bytecode

both make sure that file structure matches the program structure

reduces execution time in cases where methods are executed frequently(functions/blocks of code are called frequently like in a loop)

converts bytecode to native machine code at runtime

memory allocated on the heap that is no longer reachable by pointer

jar feature that allows the package to enforce version consistency

sealed when all the classes and source code of each class belonging to that package are stored in the same jar

result in multiple jars with a different time of creation

creating a jar with the same name and inputs multiple times will

execute a java file in another directory while you're in a different one

The first java command uses the -cp option to tell where to look for compiled code (in the jar file) and explicitly names the program (RunAnywhere) we want to look for

create/edit the main-class manifest header without needing to create or edit it first

ex: entrypoint of our jar app is class Foo, what would we put in the manifest?

class with a method with the signature public static void main(string[] args)

manifest file with:
1.Main-Class manifest header
2.listing a class(that must exist) w/ method signature:
public static void main(string[] args)
followed by a newline/carriage
return

does not contain information on other files within the jar, but can be modified to do so

used to include information from another manifest file or add custom info to the manifest during the creation of a jar file

Main.class is in a package called foo, set the entry point with the e flag

jar cfm MyJar.jar Manifest.txt MyPackage/*.class

change this to set myApp as the entrypoint

can be in any order, but no spaces between them

given this class hierarchy, what command would you use to create a jar file, given audio and images are directories?

change the directory during execution of a command

compare the effects of the -C and . options in the second command to the results of the first command:
jar cf ImageAudio.jar images audio
jar cf ImageAudio.jar -C images . -C audio .

used to avoid having to type out every file/directory name you want to include in a command, as long as there are no unwanted files in the file/directory preceding the symbol

how would we build a jar file for TicTacToe.jar if we wanted to include every file in the TicTacToe.jar directory?

show possible directories/files with names that begin with the same character

a single archive containing all the class files and auxilary resourcess needed for certain applets/applications

due to this bundling, only one HTTP transaction is needed, instead of one per file

is unique because it is a platform made purely of software that runs on top of other platforms such as

hardware or software in which a program runs, often described as a cross between the operating system and underlying hardware

provides wide array of classes for us to use in our code