Question

Computation Java question! Write a program that computes the value of
+ 1.0/(1!) + 1.0/(2!) + 1.0/(3!) + .... + 1.0/(n!)
Your program should prompt for and read from the keyboard the value of n. Compute each term from the previous term. Also include the following statement in your program:
System.out.println("e = " + Math.E);
Use type double for your computations. Run your program for n = 1, 10, 20, 50, and 100.

Answer 1

This is what I came up with so far, I need some help.
import java.util.Scanner;
class C4h4
{
public static void main(String[] args)
{
int count = 1, n, k;
double sum = 0, computation;
Scanner kb = new Scanner(System.in);
n = kb.nextInt();
k = n - 1;
computation = 1.0/(n * k);

while (count <= n)
{
computation = 1.0/(n * k);
while (k >= 1)
{
k--;
}
sum = sum + computation;
count++;
}
System.out.println("e = " + Math.E);
}
}

Answer 2

What's going on with it? Are you getting an error? Is it giving the wrong output? infinite loop?

Answer 3

Can you explain your reasoning? By that I mean, insert comments into your code. I'll add some comments to your code to show where I don't follow what's going on.

```
import java.util.Scanner;

class C4h4 {
public static void main(String[] args) {

//What is this int count = 1, n, k; line do?
//Did you mean:

//int count = 1;
//int n = 0;
//int k = 0;
int count = 1, n, k;
double sum = 0, computation;
Scanner kb = new Scanner(System.in);
n = kb.nextInt();
k = n - 1;
computation = 1.0 / (n * k);

while (count <= n) {
computation = 1.0 / (n * k);
while (k >= 1) {
k--;
}
sum = sum + computation;
count++;
}
System.out.println("e = " + Math.E);
}
}

```

Also, if you want to type code boxes like this, just use this symbol: `

use a line of 3 of them before and after a bunch of code for this effect:
```
code!
awesome
```

or you can just use one on either side of code `like this` and you can make code in your text.

Answer 4

The way I would suggest tackling this problem is by making two methods, one to calculate factorials and another to iterate through the approximation of e that you enter, which will then call the factorial method. Then print both lines one after the other:

```
System.out.println("approx e = " yourVariableHere);
system.out.println("e = " Math.E);
```

That way you're comparing your result to the constant that Java has saved.