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JAVA: Lecture # 2 Why JAVA? (ppt)
Java: Lecture # 1 Introduction To Java (ppt)
Java Lecture#2 Why Java? (doc file)
Java Lecture #1 Introduction To JAVA (doc File)
Cetogories Of Computer Languages
Characteristics Of Programming Languages
Introduction To JAVA
JAVA is not an abbreviation, High level Object-Oriented Programming Language developed by sun Microsystems run on JVM” Virtual Machine”. it is currently large powerful language but not simple.
The JAVA INTERPRETER
As a programmer we do Source Code which is high level language and what the machine understands is zeros and ones Called Object Code these are the low level instructions. Going from source to object to translate the program and make it understandable by machine to get output is due to compiler.
We know java is object-oriented language now what this object oriented is all about that the program is written in bunch of classes. Having some information about your program. Class is the encapsulation of behavior and data.
acm.Program Hierarchy
TRY FIRST PROGRAM
Import acm.graphics.*;
Import acm.program.*;
Public class FirestProgram extends GraphicsProgram {
Public void run() {
Add{ new GLabel {“My First Program”,100,75}};
}
}
Free Download Notes for Lecture#1 (.doc)
IF & Nested IF Statement
IF statement
The if statement is a powerful decision making statement and is used to control
the flow of execution of statements. If statement is similar to while loop in operation as well as in format. In both cases statements making up the body and will not be executed at all if condition is not true. And if condition is true it will execute until it become false.
Syntax
if (conditional)
{
block of statements executed if conditional is true;
}
Let’s see an example program code
/*Program will tell you what character you typed.*/
/*By Using IF Statement */
Void main (void)
{
Char ch;
Ch=getche();
If(ch==’y’)
Printf(“\n you entered y”);
}
WHERE:
-“char” is user to declare character
-“ch” means storage name in memory for character
-“getche()” use to take character form user
–“==” means equal
-“\n” use for next line
OUTPUT:
Y
YOU ENTERED Y
NESTED IF STATEMENT
If statement inside if statement is nested if statement
Syntax
{
if (conditional)
if(conditional)
block of statements executed if conditional is true;
}
Example Program Code
Void main (void)
{
If(getche()==’M’)
If(getche()==’E’)
Printf(“\you entered ME”);
}
WHERE
-“getche()” use to take character form user
–“==” means equal
OUTPUT
You Entered ME.
If Else & Nested If Else
IF ELSE STATEMENT
If statement execute single statement and else statement executes set of statements. When the test expressions or condition is true is does nothing otherwise it executes else statement.
Syntax
if (condition)
{
True-block statement(s)
}
else
{
False-block statement(s)
}
Example Program Code:
main ()
{
Int charactercount=0;
Int wordcount=1; ch;
Clrscr()
Printf(“\n\n This program will count number of characters and words you entered”);
Printf(“Type whatever you like .and press enter to see result\n\n”);
While((ch=getche())=!’\r’) {
If(ch==” ’’)
Wordcout++;
Else
Charactercout++;
}
Printf(“entered characters are :”,charactercount);
Printf(“entered words are :”,wordcount);
Getch();
}
WHERE
-“int” it declares integer
-“charactercount” you can give any name you like and it should must explicable. =0 means its value is zero. Here it will add all that characters you enter.
-“printf” what ever you write in it that appears on screen
-“clrscr()” use to clear all code above it and show result only code below it.
-“\r” use for enter
-“ch=getche()” ch is declared as character storage and =getche()means user will give input to program while it will run.
-“=!” not equal
-“ch==” <space>”” the space between inverted commas it will count words compiler will take it as word for example “Science and technology ” we can differentiate these three words due to space between them that’s why ch==”<space>”.
-“getch()” at the end it is important if use want prompt to stay till you close it.
OutPut
It depends what you entered.
Example Program Code:
if-else-if statement
void main(void)
{
int numb;
printf(“Type any Number : “);
scanf(“%d”, &numb);
if(numb > 0) {
printf(“%d is the positive number”, numb);
}
else if(numb < 0)
printf(“%d is the Negative number”, numb);
else printf(“%d is zero”,numb);
}
Out Put
It depends what you entered.
NESTED IF-ELSE STATEMENT
Use of If else inside if else statement
Syntax
{
int x,y;
For (y=1; y<12; y++)
{
For (x=1;x<10;x++)
If(y==x)
Printf(“\xDB”);
Else
If(x==12-y)
Printf(“\xB0”);
Else
}
}