Java 101

18 March 2014

In between the kit car work I have taken it upon myself to improve my java skills and hence my Android skills. I have a few apps running in the SDK and on my phone. The following excerpt I’m quite proud of as it contains a number of basic but critical java programming steps. Although I have been programming for sometime it’s always been just my way, but now I am teaching myself a structured approach, protecting variables, creating sub classes and building step by step on my capabilities and experience, resulting in better, safer code.

class Library 
{
    int size; 
    String bookTitle; 
    String authorName; 
    void lookup(){ 
        System.out.println(size + ", " + bookTitle + ", " + authorName);
        }
}

class Functions{ 
    int GiveMeARandom(int x){ int number = (int) (Math.random() * x);
    return number; 
    }
}

class Variables{
    private int varX = 0;
    private int varXupper = 100;
    private int varXlower = 0;
    public boolean setX (int x){
        boolean result = false; 
        if (x > varXlower && x<varXupper) {
            varX = x;
            result = true;
        }
        return result; 
    }

    public int getX() {
        return varX; 
        } 
} 

class TestDrive {
    public static void main(String[] args) {
        Functions func = new Functions();
        Variables var = new Variables();
        int tempNumber = func.GiveMeARandom(200);
        if (var.setX(tempNumber)) { Library d = new Library();
            d.size=var.getX();
            d.lookup(); 
        } else { 
            System.out.println("Lookup Number " + tempNumber + " out of range");
        }
    }
}