nnasino:
Hi, everyone. I was inspired by my friend and oga ezechinwa to start this thread. I will be teaching java to beginners in the house. I am not an expert but i think some knowledge can be shared.

Tools needed are jdk (java development kit), netbeans IDE and a good computer.

For jdk visit http://www.oracle.com/technetwork/java/javase/downloads/index.html
Note: please install jdk separately, do not download the jdk + netbeans bundle

For netbeans visit https://netbeans.org/downloads/


For a good computer, well visit computer village or jumia.com or if you already have one move on.

Once, you have these installed, launch netbeans. Create a new project by clicking File Menu > New Project. Set up the required information and click finish. Once you have a new project you can then run the file you are working on by using the shortcut Shift+f6.
You are now set and ready to take your first step as a java programmer.

I will encourage you to persevere, that programming is fun, stimulative to the brain, and is rewarding. The important thing is not how much or how fast you learn but how long you can keep your attention to it. With time, you will forget the beginning days.

Finally, before we start off, i will recommend that as a programmer you learn how to type. Yes, i mean it, learn how to type without looking at the keyboard. This will help you tremendously. Visit keybr.com for an online typing tool. If you can get yours hands on mavis beacon teaches typing that will also be fine and if you are from the linux world ktouch or klavaro will do.

Thanks, and welcome aboard to the tutorial.

move

stop

message

give

receive

receive(N200)

move(North, 10metres)

message("I want to buy airtime 200 etisalat"

give(N200)

receiver(Etisalat card)

message("Thank you"

move(South, 11Metres)

class HelloWorld{ //line 1
    public static void main(String[] args){ //line 2
        //Say hello to the world    line 3
        System.out.println("Hello World!"; //line 4
    } //line 5
} //line 6

/*

*/

Preboy:
finally, a java thread for beginners... #following

system.out.println("";

All

lines

public, class, void

result1

1 + 1

2

2 + 2

 4

4+4

 8

true or false

int integerNumber;
float floatNumber;
double doubleNumber;
char character;
boolean isTrue;

integerNumber = 20;

int integerNumber = 20;

int result = 1;

class Problem1{
    public static void main(String[] args){
        int result = 1; //declare and initialize result with 1
        result = result + result; // line 3
        System.out.println(result);
        result = result + result;
        System.out.println(result);
        result = result + result;
        System.out.println(result);
        }
}

String

name

String name = "Justin";

"Justin " + "Bieber" = "Justin Bieber".

nnasino:
Now, we will build our first application.
The hello world application:

class HelloWorld{ //line 1
    public static void main(String[] args){ //line 2
        //Say hello to the world    line 3
        System.out.println("Hello World!"; //line 4
    } //line 5
} //line 6

Explaining line by line:
Line 1: Java is an object oriented programming language so whatever we do MUST involve classes. We will understand classes later on but for now we will just ignore that line. Whenever creating a new file just put in your class NameOfClass and your good to go. By convention class names start with capital letter.

Line 2: public static void main(String[] args){; we will also ignore this line as we don't know enough as at now to understand it. Just know that the program starts its execution from this point. So whatever code you want to execute for now has to be between the two { } braces.

Line 3: This line is a comment. A comment is a part of your code which is not executed by the compiler. They are there to explain and describe your code. Comments are very important. When you leave a piece of code for three months and come back to it, you will realize that without
comments it might be impossible to understand exactly what is going on. Java has three kinds of comments but for now i'll explain two. The single line comment and the double line comment. The single line comment is the type we used it done using two consecutive // characters. It makes every other character after the // till the end of the line a comment. the second is the multi line comment. It spans over multiple lines and is started with a

/*

and ends with a

*/

Line 4: This prints or displays 'Hello World' to the user

Line 5: End of the public static void main.

Line 6: End of the HelloWorld class.

{} braces are used to group pieces of code together.

That's all for now. Everyone should setup their environments (netbeans, jdk). I will be taking any questions you have on setting up and the lessons so far. If you are done setting up, see if you can modify the program to display Hello Your Name instead Hello World. Remember shift f6 to run.

Cheers.

basbone:
I dont want to spoil this thread but why is java designed to first import, instantiate and declare the system.in before you use it? Thats why i fled from java. In C#, you just use Console.ReadLine(), and thats it.

basbone:
I dont want to spoil this thread but why is java designed to first import, instantiate and declare the system.in before you use it? Thats why i fled from java. In C#, you just use Console.ReadLine(), and thats it.

mgb4reel:
If i may humbly request from the OP if i could also help along the teaching process; at least, give answers to questions, give suggestions on understanding some concepts better? I have been coding in java for a while now and i understand it quit well. Will really like to help the beginners too.

sconp:
well done op. I am definitely following. I was able to run the hello world program and the continuous addition program.
They were successful.

I would try my hands on the simple interest tonight or tomorrow and paste my result here.
Keep the good work on bro.
Thanks a bunch.

sconp:
This was what I did for the simple interest. I need corrections o.

public class Simpleinterest {

public static void main (String[] args) {
double principal = 2000;
double rate = 5;
double time = 5;

double result = (principal * rate * time)/(100);

System.out.println(result);

forgive the spacing typing with my nokia phone.
Correction pls.

if(3 < 6){
    //do something
}else{
    //end the program
}

(3 < 2)
(34 > 32)
(3 == 2)
(3 <= 3)
(4 >= 3)
(5 != 0)
((4 % 2) == 0)
(true)
(false)

if(true)

boolean isReady = true;

if(isReady)

read a, b,c 
if a > 1:
    divide a, b and c by a

d = sqrt(b2 - 4 * a * c)

if d < 0:
    display "Imaginery roots"
    exit
x1 = -b + d / 2.0
x2 = -b - d /2.0

display x1 and x2

class Quadratic{
    public static void main(String[] args){
        double a;
        double b;
        double c;
        double d = 0.0;
        //Note that you could declare all of them on the same line like this: double a, b, c;
        a = 2.0;
        b = 5.0;
        c = 24.0;
        if(a > 1){
            a = a / a;
            b = b / a;
            c = c /a;
            //When you have this kind of situation, you can write b /= a, c /=a, a += c, b -= c etc
        }
        d = Math.pow(b, 2) - 4 * a * c;
        if (d < 0){
            //if d is negative then there will be imaginery numbers which we are not supporting currently
            System.out.println("Imaginery roots";
        }else{
            d = Math.sqrt(d);
            double x1 = -b + d / 100;
            double x2 = -b - d /100;
            System.out.println("The roots are: " + x1 + "  and " + x2);
        }        
    }
}

JAGZZ:
nnasino, Please help with this question: Write a program to sum ten integers using Java

class Sum{
    public static void main( String[] args){
    int sum = 0;
    for(int I = 1; I <= 10; I++){
       sum += I;
    }
    System.out.println("Sum of first ten numbers: " + sum);
}
}

JAGZZ:
nnasino, Please help with this question: Write a program to sum ten integers using Java

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

public class SumIntegers{
          
                    public static void main(String args[]){
                         Scanner input = new Scanner(System.in);    //creates an object of the Scanner class to take input from keyboard
                         int number;    //the integer declaration
                         int sum = 0;   //declares the sum integer and initialize it to zero
                         
                          for(int i = 1; i <= 10; i++){              //repeat the enclosed instructions 10 times
                        
                              System.out.println("Please enter an integer:";
                              number = input.nextInt();     //takes the integer from the user
                              sum = sum + number;         //performs the addition operation
                          
                         }

                      System.out.print("The sum of the ten integers entered is: " + sum);


                    }

}

nnasino:

I don't really understand your question. Do you mean to sum the first ten integers? If so then this will work:

class Sum{
    public static void main( String[] args){
    int sum = 0;
    for(int I = 1; I <= 10; I++){
       sum += I;
    }
    System.out.println("Sum of first ten numbers: " + sum);
}
}

If you just want to sum ten arbitrary integers then simply add them using +. Hope this helps

mgb4reel:

The Op has done justice to the problem but the question is somehow. If what you mean is: a program to take ten integers from the user and sum them, then the solution goes thus:

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

public class SumIntegers{
          
                    public static void main(String args[]){
                         Scanner input = new Scanner(System.in);    //creates an object of the Scanner class to take input from keyboard
                         int number;    //the integer declaration
                         int sum = 0;   //declares the sum integer and initialize it to zero
                         
                          for(int i = 1; i <= 10; i++){              //repeat the enclosed instructions 10 times
                        
                              System.out.println("Please enter an integer:";
                              number = input.nextInt();     //takes the integer from the user
                              sum = sum + number;         //performs the addition operation
                          
                         }

                      System.out.print("The sum of the ten integers entered is: " + sum);


                    }

}

JAGZZ:


Yeah its to sum up any ten integers from the user. Thanks, I appreciate.

mgb4reel:

The Op has done justice to the problem but the question is somehow. If what you mean is: a program to take ten integers from the user and sum them, then the solution goes thus:

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

public class SumIntegers{
          
                    public static void main(String args[]){
                         Scanner input = new Scanner(System.in);    //creates an object of the Scanner class to take input from keyboard
                         int number;    //the integer declaration
                         int sum = 0;   //declares the sum integer and initialize it to zero
                         
                          for(int i = 1; i <= 10; i++){              //repeat the enclosed instructions 10 times
                        
                              System.out.println("Please enter an integer:";
                              number = input.nextInt();     //takes the integer from the user
                              sum = sum + number;         //performs the addition operation
                          
                         }

                      System.out.print("The sum of the ten integers entered is: " + sum);


                    }

}

nnasino:

Thanks boss, for the answer

nnasino:

Thanks boss, for the answer

while

do while

for

switch

while

while(condition)
    statement;

statement

while(condition){
    statement;
    statement;
    statement;
    ....
    statement;
}

Do while

do
   statement;
while(condition);

 for loop

for(initialization; condition; iteration)
    statement;
or 
for(initialization; condition;iteration){
    statements;
    statements;
    ......
    statements;
}

switch(variable):
case constant1:
      statement;
      statement;
      ...
      break;
case constant2:
      statement;
      statement;
      ...
      break;
case constant3:
      statement;
      statement;
      ...
      break;
case constantn:
      statement;
      statement;
      ...
      break;
default:
      statement;
}

while

int count = 1;
while(count <= 10){
    System.out.println("The square of " + count + " is " + (count*count));
    count++;
}

for(int count = 1; count <= 10; count++){
    System.out.println("The square of " + count + " is " + (count*count));
}

mgb4reel:

The Op has done justice to the problem but the question is somehow. If what you mean is: a program to take ten integers from the user and sum them, then the solution goes thus:

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

public class SumIntegers{
          
                    public static void main(String args[]){
                         Scanner input = new Scanner(System.in);    //creates an object of the Scanner class to take input from keyboard
                         int number;    //the integer declaration
                         int sum = 0;   //declares the sum integer and initialize it to zero
                         
                          for(int i = 1; i <= 10; i++){              //repeat the enclosed instructions 10 times
                        
                              System.out.println("Please enter an integer:";
                              number = input.nextInt();     //takes the integer from the user
                              sum = sum + number;         //performs the addition operation
                          
                         }

                      System.out.print("The sum of the ten integers entered is: " + sum);


                    }

}