Programming Language 3

mongooseriverSoftware and s/w Development

Jun 7, 2012 (5 years and 5 months ago)

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Programming Language
3
Programming Language
3

A programming language is an
artificial
language
that can be used to
control
the
behavior
of a machine, particularly a
computer.

PLs should support

Data type
,
Sequence control
,
Object
,
Class
, ...

Java is an OOPL.
Interpret vs. Compile
4
Interpret vs. Compile
4

Compile


The program written
in a language is
translated
to another
language by another
program named
compiler
.

Interpret

The program written
in a language is
executed
statement
by statement by
another program
named
interpreter
.
5
C
C
Pascal
Pascal Compiler for Linux
C Compiler for Mac
C Compiler for Windows
Pascal Compiler for
Windows
Pascal Compiler for Mac
C Compiler for Mac
C Compiler for Linux
C Compiler for Mac
C Compiler for Mac
Platform and Compiler
Platform
Independency
6
Slot 1
Slot 2
Slot 3
The
Device
Platform
Independency
6
Slot 1
Slot 2
Slot 3
The
Device
When we have different
platforms and a single device,
what can we do to support this
device on all platforms?
Platform
Independency
6
Slot 1
Slot 2
Slot 3
The
Device
When we have different
platforms and a single device,
what can we do to support this
device on all platforms?
Entering the Java world!
Edit your java files
Compile your files
Run the class file
Java file
Class file
7
Entering the Java world!

A Java file contains a
class
.

A
class
contains a
main

function.

Java file compiled to
byte
code
file (class file)

You can
run
your class.
Edit your java files
Compile your files
Run the class file
Java file
Class file
7
1
st
Exercise
8
/*
* This is your first java program.
*/
class
HelloWorld
{
public static void main(String[] args){
System.out.println(“Hello World!”);
}
}
Edit your java file
9
Edit your java file

Any
editor
can be used

VIM, Gedit, Textpad, Kedit, Textedit,
Notepad, ...

It’s much more simpler if you use an IDE

Eclipse, IDEA, Forte, NetBeans, ...

Java files have .java extension.
9
Java Compilation
10
Java Compilation
10

The Java Compiler
(
javac
) is used to
compiler Java sources into
byte code
files.

javac
is just available in the Java SDK not
JRE.

Byte code
files have
.class
extension.

Byte code
is the
assembly language
for the
Java Virtual Machine (JVM).
Compile HelloWorld
11
$javac HelloWorld.java
Compile HelloWorld

Java files can be
compiled with javac
(Java
Compiler)

Now a file named
HelloWorld.class is
generated.
11
$javac HelloWorld.java
Running Java Classes
12
Running Java Classes

Java Virtual Machine (JVM)
is used for
running class files.

JVM can run class files.

Now, there are officially supported JVMs
for
Linux
,
Windows
,
Mac

OS

X
and
Solaris
.

JVM is also available for
FreeBSD
,
AIX
,
Darwin
, ...
12
Run HelloWorld
13
$java HelloWorld
Run HelloWorld

Use
java
to run the
class file.
13
$java HelloWorld
Any Questions?