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Introduction to Programming
Languages
Problem Solving in
Programming
Problem Solving
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Primitive and Higher calculations
Computer programming is artifact (tool) used
for the Problem solving mechanism via
computers
Few Terms
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Program
Programming
Programability
Algorithm and program
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Algorithm is sequence of steps usually written
in natural language readable for humans
Programming is the algorithm translated in
programming language so that computer can
understand
Programming – By Example
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Mean of three Numbers
Instructions
Program Counter
Fetch and Execute Cycle
Flow Charts
FlowCharts
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Is common type of chart used to represents
an algorithm or process.
The steps are shown in boxes of various
kinds, and their order by connecting these
with arrows.
Flowcharts are used in analyzing, designing,
documenting or managing a process or
program in various fields.
Flowchart
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The notations for flowchart are
Process
Start / End
Decision
Input / Output
T
F
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Draw a flowchart that will compute the sum, average and
product of three numbers.
How to develop Algorithm
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Write Algorithm and draw flow chart of 10
numbers in a loop
Table of 2
Factorial
Jumping to Programming Languages
History (Paradigms)
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Unstructured Languages
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Structured / Procedural Languages
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Single continuous block of code
e.g Assembly
Functions and procedures
e.g C, Pascal, Fortran
Object-Oriented Languages
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Real-world modeling (Attributes, Behavior)
e.g C++, Java
Why we are going towards OOP?
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Object-oriented creatures
Advantages:
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Simpler, easier to read programs
More efficient reuse of code
Faster time to market
More robust, error-free code
Concepts on the way ….
some basic questions??
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What are the objects in OOP?
What should be the objects in the design of
an object-oriented program?
Is OOP better than previous programming
paradigms?
How will I understand?????
Computer and Humans
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Computers understand 0’s and 1’s
High level Language
Machine level Language
Execution of a Program
Source Code
Other Object Files
Execute
Compiler
.exe file
Linker
Object Code
010101010
101010101
101000000
……
MyProg.java
public class Sample
{
public void main()
{
println( “hello”);
}
}
Java Interpreter
Other class Files
A2 HJ JI
NJ JI JO
JO 99 O1
JVM
Compiler
JAR Archive
Linker
MyProg.class
AB CD F3
S6 JS JH
N9 J5 33
A2 N8 BH HJ
BK JI KO O9
NJ JK L8 J9
JI JO KJ KO
K3 K9 98 90
….
Java
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OOP language developed by SUN Microsystems
Java is compiled into bytecodes
Bytecodes are high-level, machine-independent
instructions for a hypothetical machine, the Java
Virtual Machine (JVM)
The Java run-time system provides the JVM
Extensive networking facilities
Extensive set of APIs for GUIs, distributed
computing, 2D/3D graphics, mail, and others
Portable: Write Once, Run Anywhere
Multithreading support built into the language
Java Features
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Automatic garbage collection
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No pointers or pointer arithmetic
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No off-by-one bugs
Arrays are first-class objects
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No manual memory allocation and deallocation
Never have to worry about memory leaks
Array bounds are always checked
Multiple inheritance replaced by interfaces
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Eliminates complexities of multiple inheritance
Java Virtual Machine
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Java is compiled into bytecodes
Bytecodes are high-level, machine-independent
instructions for a hypothetical machine, the Java Virtual
Machine (JVM)
The Java run-time system provides the JVM
The JVM interprets the bytecodes during program
execution
Since the bytecodes are interpreted, the performance of
Java programs slower than comparable C/C++ programs
But the JVM is continually being improved and new
techniques are achieving speeds comparable to native
C++ code
JVM
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All Java programs run on top of the JVM
JVM was first implemented inside Web browsers, but
is now available on a wide variety of platforms
JVM interprets the bytecodes defined in a machineindependent file format called a class file
Types Of Java Programs
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Application
Standalone Java program that can run
independent of any Web browser
Applet
Java program that runs within a Java-enabled
Web browser
Servlet
Java software that is loaded into a Web server
to provide additional server functionality
Instructions for Java Installation
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Download and Install
JDK
NetBeans 6.7.1
Refference Book
The Complete Reference
Java 2 Fifth Edition. By Herbert Schildt
Hello World
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class HelloWorld
{
public static void main(String args[])
{
System.out.println("Hello World");
}
}
Factorial
public class Factorial2
{
public static void main(String args[])
{
int n = 3;
int fact = 1;
for (int c = 1 ; c <= n ; c++ )
fact = fact*c;
System.out.println("Factorial of "+n+" is = "+fact);
}
}
Table of Two or not ?
public class tables
{
public static void main(String args[])
{
for (int i = 1; i <= 10; i++) {
for (int j = 1; j <= 10; j++) {
System.out.print(i + "x" + j + "=" + (i * j) + "\t");
}
System.out.println();
}
}
}
Tables Output
Tasks
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Just print Table of Two.
Find Factorial with proper solution as output
like 5! = 5 x 4 x 3 x 2 x 1 = 120.
Each new term in the Fibonacci sequence is
generated by adding the previous two terms.
By starting with 1 and 2, the first 10 terms will
be: 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
Write a program to find out if a number is
prime?