BASIC ARRAY of STRING

Let's say we will make a program that will get the name of every employee. Let's say we have 10 employees. To get every name of them, we will simply declare 10 String variable that will hold the inputted names of them. But what if, there's 20? are we going to declare 20 variables too? what if there's 50, a hundred or even a thousand or more? Using an array will lessen the variables that will be declared to hold every inputted data of the same type.

Any ways, in simple definition, Array holds multiple number of data of the same type within just one variable. Below, I will show you some basics on using of an array.

import java.util.Scanner;

public class UsingBasicArray

{

public static void main (String[] args)

{

String namesOfEmployees[] = new String[5];

//inside the square bracket is the array length. 

//I just made it 5 to make it short, 

//but you can make it even a hundred 

//or more depending on your necesity.

int ctr;

Scanner in = new Scanner(System.in);//Scanner is being instantiated here.

for(ctr=0;ctr<namesOfEmployees.length;ctr++)

{

System.out.print("Enter employee "+(ctr+1)+" name: ");

namesOfEmployees[ctr]=in.nextLine();

//right here, while the loop rotates

//you are actually locating where to put

//values in the array.

//ctr represents the index of where in you will

//put the inputted value.

}

for(ctr=0;ctr<namesOfEmployees.length;ctr++)

{

System.out.println("Employee "+(ctr+1)+" is "+namesOfEmployees[ctr]);

//right here is where you will call the values from

//every indices the inputted values are located.

//again, the ctr represents the index of the value

//that you are getting to display.

}

}

}

Here is a sample output of this source-code:

Enter employee 1 name: Marcelino Nyeto
Enter employee 2 name: Axle Dinozo
Enter employee 3 name: Mc Gyver
Enter employee 4 name: Allen Anatawa
Enter employee 5 name: Jhayvee Rozan

Employee 1 is Marcelino Nyeto
Employee 2 is Axle Dinozo
Employee 3 is Mc Gyver
Employee 4 is Allen Anatawa
Employee 5 is Jhayvee Rozan

From this you can experiment to make it broader. It's up to how your imagination can go... Good luck...

making an inverted half triangle in java using forloop

public class halfinvertertri
{

public static void main (String[] args)
{
String str = "*";
String st = "*";
int row;
int col;

for(row=5;row>0;row--)
{
for(col=1;col<=row;col++)
{
System.out.print(" ");
}

System.out.print(str);
str = str + "*";
System.out.println ("");
}
}
}

OUTPUT WILL BE:


      *
     **
    ***
   ****
  *****

try it yourself and try to make an experiment out of this example

making half triangle with java using forloop

public class halftri
{
public static void main (String[] args)
{
for(int row=1;row<7;row++)
{
for(int col=1;col<=row;col++)
{
System.out.print("*");
}
System.out.println ("");

}
}
}

output will be:


*
**
***
****
*****
******

try it yourself and make some experiment out of this example....

example of an operational loop(the "for" loop)

//Display the sum of even numbers from 1-100.

public class operationalloop

{

public static void main (String[]args)

            {

              int a,b,sum=0; //declaring variables(make sure you initialized the value of the sum for you will be                                      //using it as a container in the body of the program.

              

              for(a=2;a<=100;a+=2)

              {

                    sum=sum+a; //this is where you add up to the value of sum

/*note:

       This is how the looping goes:

       it will be read as - "(initialization) a=2, if (logical test)a<=100 then (operation) sum=sum+a, (increment) a+=2)*/

               }

              System.out.println("the sum is "+sum); //this is how to display the sum

            }

}

OUTPUT WILL BE:
the sum is 2550

Display "Hello World!"

public class helloworld
{
public static void main (String[]args)
            {
              System.out.println("Hello World!");
            }
}

OUTPUT WILL BE:
Hello World!