[U]Integer Types (from smallest to largest)[/U]

byte

short

int

long

[U]Floating Point Types[/U]

float 

double

[U]String Types

[/U]char

String



And then also there is the boolean, not sure what type it is though.

     public static void main(String[] args) 

{ 

//code in here 

By the way, two slashes like this //  is a comment and will not be read as code by your program. You can also do a multi - line comment by doing this



/*

 * Comment in here

* etc

*/



}

    

System.out.println("");  //prints out whatever string is inside the "". The println means it will print on that line. Which means it will go to a new line each time

System.out.print("");  //Just using print means it prints out and does not go to a new line

    

\n - new line

\t - tab

\b - backspace/r - return

\'  - Inserts a single quote

\"  - Inserts a double quote

\\  - Inserts a backslash 

    

public class FunWithString

{

    public static void main(String [] args)

    {

        System.out.println("This is a String"); //String is an object data type

        

        System.out.print("Roses are Red, ");

        System.out.println("Violets are Blue, ");

        System.out.println("\tbut I have a \"committment\" issues");

        System.out.println("so I think we should be friends, \nat this point in our relationship\\journey.");

        

        

        System.out.println("This is concatenation " + 24 + 45);

        System.out.println("This is adding " + (24+45));

        int num1 = 10;

        System.out.println("The total is: " + num1 + " boxes.");

        

        String s1 = "The total is: ";

        String s2 = "Banana";

        String s3 = "Apple";

        String s4 = "Orange";

        String s6 = "Apple";

        

        System.out.println(s2 + s3);

        System.out.println(s3.concat(s4));

        System.out.println(s4.length());

        System.out.println(s4.substring(1,4));

        String s5 = s4.substring(1, 2);

        System.out.println(s5);

        char c1 = s4.charAt(1);

        System.out.println(c1);

        System.out.println(!(s4.equals(s6)));

        

        s4 = s4.toUpperCase();

        

        s3 = s3.toLowerCase();

        

    }

}

    

public class Class1

{//Start class

    public static void main (String[] args)

    {//Start main

        System.out.print("Hellow World!");

        System.out.println("Yay!");





        //Integer Data Type - Primitive Data type

        // 4 integer data types - byte, short, int, long ///////////////////////////////

        byte b1; //assigned

        b1 = 0; //initialized //256

        short s1 = 0; //assigned and initialized

        int num1 = 0;

        long dig1 = 0;





        int num2 = 0, num3 = 4, num4 = 7;

        byte b2, b3 = 10, b4 = 1;





        int dayOfWeek = 1; //good variable name

        int totalPay = 0;

        int NUMBER_OF_WIDGETS = 0;





        //Floating Point Variables - Primitive Data Types //////////////////// float, double

        float f1 = 0.0F;

        double d1 = 0.0D;





        int iResult = 0;

        double dResult = 0.0;





        iResult = 4/3;

        dResult = 4/3; //assignment conversion

        System.out.println(iResult);

        System.out.println(dResult);





        dResult = 4.0/3;  //Arithmetic Promotion





        float fResult = (float)4.0/(float)3.0;

        iResult = (int)(4.0/3.0);  //casting





        System.out.println(dResult);





        System.out.println(4.0/3.0);

        System.out.println(4.0F/3.0F);

        num2 = 4;

        num2++;  //num 2 = num2 + 1;

        System.out.println(num2);

        System.out.println(++num2);





        System.out.println(num2--);

        System.out.println(num2);

        System.out.println(--num2);





        /*Operations on integers: +, -, *, /, %, ++, --, +=, -= , *=, /=   */





        num2 = 5;

        num2*=3;  //num2 = num2 * 3;

        System.out.println(num2);





        num2-=7;  //num2 = num2 - 7;

        System.out.println(num2);





        num2 %= 3;

        System.out.println(num2);





        float f2 = 0.0F;

        f2 = 1.0F;

        System.out.println(f2);





        //Primitive Data Type: boolean





        boolean flag = true;

        boolean bool1 = false, boo2;





        /*boolean operators: == "equal to"

         * != "not equal"

         * && "and"

         * ! "not"

         * || "or"

         * > "greater than"

         * < "less than"

         * <= "less than or equal to"

         * >= "greater than or equal to"

         */





        //Primitive Data type: character

        char c1 = 'a';

        char c2 = 'A',c3,c4='#';





        //Operations with characters: <, >, <=, >=, =, !=





        System.out.println('a'=='A';

    }//End main

}//End class

//End file

    

import java.util.Scanner;//imports the scanner class

import java.text.DecimalFormat;//imports the decimal formatter

public class UserInput

{

    public static void main(String[] args)

    {

        Scanner scan = new Scanner(System.in);//Declares the Scanner in scan

        

        System.out.println("Enter a number: ");

        int num = scan.nextInt();//so scan.nextInt takes in an integer and stores it in num

        

        scan.nextLine();//takes in a string

        

        System.out.println("What is your name?");

        String name = scan.nextLine();//takes in the string and stores it in name

        

        System.out.println("Enter a decimal:");

        double dec = scan.nextDouble();//takes in the decimal and stores it in dec

        

        System.out.println("num = " + num + ", name = " + name + ", and dec = " + dec);//prints out all the things that were entered by the user

        

        

        DecimalFormat decFormat = new DecimalFormat("0.00");//2.00, it will always put .00

        //("0.##") will put 0.number

        //("0000") = 0001 when 1 is entered

        

        /*f2 = (float)4/5 = 0.8

        f2 = (float)(4/5) = 0.0

        

        import java.text.NumberFormat;

        NumberFormat percent = NumberFormat.getPercentInstance();    

        */

    }

}