INPUT-OUTPUT OPERATIONS:
========================
INPUT OPERATIONS

java.io ==> System.in
System.out & System.err ==> Output operations

System.out
	three built-in methods:
		1) println()
		2) print()
		3) printf()

Value of a = 123

String Datatype:
================
==> group of characters which enclosed with double quotes.
ex: "string"
Syntax for string variable declaration is:
	String name-data = "value";
name-data.lowercase

1) println()
============
==> an built-in method from "java.io" package.
==> a module "System.out"
Syntax:
	System.out.println("text");

==> to print/write/display anything on the screen/console println() can use.
==> println ==> print line
Ex: printf("\n");

class outputOperations{
    public static void main(String x[])
    {
        int a = 123;
        byte b = 112;
        
        System.out.println(a);
        System.out.println(b);
    }
}

==> that every definition of println() can reserve with new line by default.
Ex: println("hi");
println("hello");

output:
======
hi
hello

Aspect-1: 
printing only the text.
=========================

class outputOperations{
    public static void main(String x[])
    {
        // printing of text
        String s = "Hello";
        
        System.out.println(s);
        System.out.println("Hi all.");
        System.out.println("Welcome To Ashok IT.");
    }
}

class outputOperations{
    public static void main(String x[])
    {
        // printing of multiple strings using single println()
        
        String s1 = "Hi all";
        String s2 = "Welcome To Ashok IT";
        
        System.out.println(s1 + " " + s2);
    }
}

Aspect-2:
=========
the text along with result
sample-op: Hi, my name is ravi.
value of a = 123 and value of b = 112

String Concatenation:
====================
==> Joining of two or more strings into one unit is called as "String concatenation".
==> Symbol: +
Syntax:
	str1 + str2

Rules:
======
1) String with number (Integral/float)
number + string
string + number

string1 + number + string2

class outputOperations{
    public static void main(String x[])
    {
        // concatenation of string with number
        
        String name = "Raju";
        int age = 23;
        
        System.out.println("Hi" + " " + "I am " + name + ".I am " + age + " years of old.");
    }
}

======================================

2) print()
==========
which can use to write/print anything on the screen/console.
==> with multiple print() definitions, we can get the result with single line.

Ex: print("Hi");
print("Ravi");
"HiRavi"

=============================

Assignment:
===========
WAP to take two integers as an input and print their sum along with inputs.

Sample Output:
==============
inputs:
	a = 12
	b = 24
Output:
	Sum of 12 and 24 is = 36.

====================================================
3) printf()
===========
Syntax:
	System.out.printf()

Format Specifiers:
==================
int ==> %d/%i
long ==> %ld
string ==> %s
char ==> %c

class outputOperations{
    public static void main(String x[])
    {
        // text using printf()
        int n = 123;
        float f1 = 1.23f;
        float f2 = 1.223f;
        
        System.out.printf("%s","Hello\n");
        System.out.printf("Hello");
        System.out.printf("The Given Integer value is = %d\n",n);
        
        System.out.print("Hi all."+"\n"+"Welcome To Ashok IT.");
        System.out.print("f1 = "+f1+"\t" + "f2 = "+f2);
    }
}

============================================

Identifiers:
============

Variable:
	datatype name-of-data = value;

==> a name
	which we can use to name any entity like: variables, methods, class, objects in the program.

Rules for an Identifiers:
=========================
1) Should contains:
	alphabets : Upper case/Lower case/both
2) should contains:
	digits: 0 to 9
3) should include:
	special characters:
		underscore sign (_)
		dollar sign ($)
ex: abc_12, abc ==> valid identifiers

4) never begin with digit, but it can be begin with: alphabet/_/$
ex: 97abc = 123 ==> Invalid

5) never include: other special characters like: space, .!@
ex: abc@we = 123; ==> Invalid

6) Never define with keywords.
Ex: import = 122; ==> Invalid

7) Case Sensitive
Ex: ravi (lower case)
Ravi (mixed case)
RAVI (upper case)

8) no limit in length of an identifier.

class Identifiers{
    public static void main(String x[])
    {
        byte abc = 127;
        // short 97abc = 1223; Syntax Error
        short $_s = 1122;
        // int abc@we = 112233;
        // long private = 123l;
        long PRIVATE = 123l;
        boolean bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb = true;
        
        System.out.println(bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb);
    }
}