Simple Java Tutorial.

About this tutorial.

• This Java tutorial is about using for-loop and indirect indexing with help of a String array.
• If you just want to look through the solution of this tutorial you can download it here.

Need to know before this.

• Basic knowledge about HTML and CSS.
• You should have learned and understood everything under Java Basic.

Regarding all zip files for download.

• All tutorials contains a Netbeans IDE project with code examples.
• Needed tools for all examples/tutorials can be found in the right menu on this page.

Create a Netbeans project

• As first action we need to create a project in Netbeans with the name Java01, which contain a java main class with the name app.MainFile.

Creating the Java Application.

1. In the Netbeans open the MainFile.java file (if it is not open already).

   We need a String array that we shall do some indirect indexing on.

2. Copy then this code into the main() method:

      String[] verbs = {"composite ", "a ", "This ",
      "using ", "index!", "is ",
      "indirect ", "string "};
   

   This is an array of words that we want to reorganize and print as:
   "This is a composite string using indirect index!".

   We need an array of indexes to reorganize the word.

3. Copy then this code as next statement in the main() method:

      int [] index = {2, 5, 1, 0, 7, 3, 6, 4};
   

   We have now the data indexes to print our resulting sentence using an enhanced for loop.

4. Copy then this code as next statement in the main() method:

   // We use the index array to find the right word 
   // in the verbs array and print each word on the standard output 
    for (int i : index) {
      System.out.print(verbs[i]);
     }
   
     System.out.print('\n');
   

   It is possible of course to use other loop types as well.

5. You can copy this code at the end of the main method to try it out:

     // The same with a general for loop
     for (int i=0 ; i<index.length ; i++) {
      System.out.print(verbs[index[i]]);
     }
   
     System.out.print('\n');
   
    // The same with a while loop
     int i=0 ;
     while (i<index.length) {
      System.out.print(verbs[index[i]]);
      i++;
     }
   
     System.out.print('\n');
   
    // The same with a do-while loop
     int x=0 ;
     do {
      System.out.print(verbs[index[x]]);
      x++;
     } while(x < index.length);
   
     System.out.print('\n');
   

Running the Java Application.

1. Right click the project, Java01, and select run from the menu.

This is a composite string using indirect index!