import java.io.*;
/*
* Like Ruby, in java, everything is an object. To write a program, you'll need to
* start by declaring a class. As in C, our program execution starts with the main
* function. Also like C, Java is a compiled language, so you'll need to compile
* the code and then run the class using the java interpreter.
*/
class Fibonacci {
/*
* So here we are defining the main function. Remember that this is supposed to
* actually run this program, so the function needs to be `public`, in addition,
* it's `static`, meaning we can call this method without an object of the Fibonacci
* class being instantiated, and it doesn't need to return anything, as it will
* run by the interpreter, which will handle the exit status.
*/
public static void main(String args[]) {
/*
* We are using System.out.println here, but newer versions of Java have the printf method.
*/
System.out.println("How many numbers of the sequence would you like?");
/*
* I'm sure there's more than one way to skin a cat, but to read stdin here, we
* are creating a new BufferedReader, which will read one line of input.
*/
InputStreamReader sr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(sr);
//BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
/*
* Now here is a concept we haven't addressed yet. The java compiler complains if
* you try to call a method that could throw an exception (error), so I've included
* an example here of how to handle the exceptions that could be thrown. Also, like
* in our previous examples, we are casting the input to an integer.
*/
try {
String input = br.readLine();
int num = Integer.valueOf(input).intValue();
//String userInput = in.readLine();
//Console console = System.console();
//String username = console.readLine("User: ");
if(num==5)
fibonacci(num);
else
{
if(num<=0)
System.out.println(" " + num + " is not a valid argument. You must specify a positive integer to print out numbers in the series");
}
} catch (NumberFormatException e){
System.out.println("That is not an integer. Please enter an integer value");
} catch (IOException e) {
System.out.println("I did not recieve an input");
}
}
/*
* So here is our Fibonacci function. like the main function, it is public and can be
* called without creating a Fibonacci object. We've also introduced a new method of
* calculating the sequence without using a temporary variable. In a later post, I will
* examine the different algorithms used to calculate the Fibonacci sequence, and compare
* performance in multiple languages.
*/
public static void fibonacci(int num){
int a=0,b=1;
for (int i=0;i<num;i++){
System.out.println(a);
a=a+b;
b=a-b;
}
}
public static void prime(int num) {
int i;
for (i=1; i < num; i++ ){
int j;
for (j=2; j<i; j++){
int n = i%j;
if (n==0){
break;
}
}
if(i == j){
System.out.print(" "+i);
}
}
}
}
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