Java Tutorial Day 1 (Hello World)
Learning Objective: Let’s start with Java Fundamental and Understand its syntax and usages in real life applications.
funda1.java
public class funda1{
public static void main(String[] args)
{
System.out.println("Hello");
}
}
funda2.java
/*
* Variable Rules
*
* Names can contain letters, digits, underscores, and dollar signs
* Names must begin with a letter
* Names should start with a lowercase letter and it cannot contain whitespace
* Names are case sensitive ("Name" and "name" are different variables)
* Do not use Reserved words (like Java keywords, such as int or boolean) cannot be used as names
*
* Data Types Supported: String, int, float, char, boolean
*/
public class funda2{
public static void main(String[] args) {
System.out.println("---------------------------------");
System.out.println("int Variable Example");
int mark = 10;
System.out.println("Mark is :" + mark);
System.out.println("---------------------------------");
System.out.println("String Variable Example");
String fname = "Adarsh";
String lname = "Patel";
System.out.println(fname + " " + lname);
}
}
funda3.java
/*
* Operators Supported in java
*
* + Addition
* - Subtraction
* * Multiplication
* / Division
* % Modulus
* ++ Increment
* -- Decrement
*
*/
public class funda3{
public static void main(String[] args) {
int no1 = 10;
int no2 = 20;
System.out.println("---------------------------------");
System.out.println(" Operator Examples");
System.out.println("---------------------------------");
System.out.println("no1 is: " + no1 + ", no2 is: " + no2);
System.out.println("---------------------------------");
System.out.println("+ :" + (no1+no2));
System.out.println("- :" + (no1-no2));
System.out.println("* :" + no1*no2);
System.out.println("/ :" + no2/no1);
System.out.println("% :" + no2%no1);
System.out.println("++ (postfix) :" + no1++);
System.out.println("++ (prefix) :" + ++no1);
System.out.println("-- (postfix) :" + no1--);
System.out.println("-- (prefix) :" + --no1);
System.out.println("---------------------------------");
}
}
funda4.java
public class funda4{
public static void main(String[] args) {
int no1 = 0;
System.out.println("---------------------------------");
System.out.println(" Conditional Structures");
System.out.println("---------------------------------");
System.out.println("no1 is: " + no1);
System.out.println("---------------------------------");
if(no1>0)
{
System.out.println("no1 is positive");
}
else if(no1<0)
{
System.out.println("no1 is Negative");
}
else
{
System.out.println("no1 is zero");
}
if(no1==0)
{
System.out.println("no1 is zero");
}
else
{
System.out.println("no1 is Non Zero");
}
System.out.println("---------------------------------");
}
}
funda5.java
public class funda5{
public static void main(String[] args) {
int no1 = 5;
int i;
System.out.println("---------------------------------");
System.out.println(" For and While Loop");
System.out.println("---------------------------------");
System.out.println("no1 is: " + no1);
System.out.println("---------------------------------");
System.out.println("For Loop Example");
for(i=1;i<=no1;i++)
{
System.out.println(i);
}
System.out.println("While Loop Example");
i=1;
while(i<=no1)
{
System.out.println(i);
i++;
}
System.out.println("---------------------------------");
}
}
funda6.java
public class funda6{
String name = "";
int mark1=0,mark2=0,mark3=0;
public static void main(String[] args) {
System.out.println("---------------------------------");
System.out.println(" Class / Object Example");
System.out.println("---------------------------------");
System.out.println("Student Object Details");
prog6 std = new prog6();
std.name = "Adarsh";
std.mark1 = 50;
std.mark2 = 60;
std.mark3 = 70;
System.out.println("Name: " + std.name);
System.out.println("Mark1: " + std.mark1);
System.out.println("Mark2: " + std.mark2);
System.out.println("Mark3: " + std.mark3);
System.out.println("---------------------------------");
prog6 std2 = new prog6();
std2.name = "Raj";
std2.mark1 = 70;
std2.mark2 = 80;
std2.mark3 = 90;
System.out.println("Name: " + std2.name);
System.out.println("Mark1: " + std2.mark1);
System.out.println("Mark2: " + std2.mark2);
System.out.println("Mark3: " + std2.mark3);
System.out.println("---------------------------------");
}
}