For loop, dividing one

Question

I have tried this in Javascript and have gotten my answers, but the answer I need must be more exact. I am trying to divide 1 by every number between 2 and 1000, and simply print them.

public static void main(String [] args) {
    for (int i=2;i<=1000;i++){
        double g = (1/i);
        System.out.println(g); // print "1/1,2,3,4.....1000" 
    }
}

I haven't done Java in a while, so I forget my correct variable names.

score 4 · Answer 1 · answered Dec 15 '13 at 06:35

Since both 1 and i are integers, integer division is being used. Either 1 or i need to be double in the 1/i section of your code so that integer division is not used. You can do something like 1.0/i or 1/((double) i) to ensure that float division is used instead.

score 2 · Answer 2 · answered Dec 15 '13 at 06:26

2

replace 1 by 1.0D that will result into double

answered Dec 15 '13 at 06:26

jmj

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The `D` suffix is optional for a `double`. – Ted Hopp Dec 15 '13 at 06:28
just to make it readable – jmj Dec 15 '13 at 06:28
I need it to be more exact than that, but at least a number is coming up now. Thanks. – user2962770 Dec 15 '13 at 06:28
if you need more precise answer go for `BigDecimal` – jmj Dec 15 '13 at 06:29
@user2962770 or you can use [`BigFraction`](http://www.vacant-nebula.com/code/BigFraction.java.source) (see http://stackoverflow.com/questions/474535/best-way-to-represent-a-fraction-in-java/474612#474612) – Justin Dec 15 '13 at 08:13

Nambi · Answer 3 · 2013-12-15T06:32:29.780

0

try this

public static void main ( String args[] )  {

            for (int i=2;i<=1000;i++){
                double g = (1.0/i);
                System.out.println("1/"+ig); 
            }

output: 0.5 0.3333333333333333 0.25 0.2 0.16666666666666666 0.14285714285714285 0.125 . . . .

edited Dec 15 '13 at 06:32

answered Dec 15 '13 at 06:27

Nambi

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Elliott Frisch · Answer 4 · 2013-12-15T06:41:44.240

0

I would do something like this (note you can have as many digits of precision as you like) utilizing BigDecimal.

public static void main(String[] args) {
  java.math.BigDecimal ONE = java.math.BigDecimal.ONE;
  // 50 digits of precision.
  java.math.MathContext mc = new java.math.MathContext(50);

  for (int i = 2; i <= 1000; i++) {
    java.math.BigDecimal divisor = new java.math.BigDecimal(i);
    java.math.BigDecimal result = ONE.divide(divisor, mc);
    result.round(mc);
    System.out.printf("%d/%d = %s\n", 1, i,
        result.toString());
  }
}

edited Dec 15 '13 at 06:41

answered Dec 15 '13 at 06:32

Elliott Frisch

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BigDecimal was the variable I was looking for, http://ideone.com/7FBtUL I tried on IDEone, and it didn't work... – user2962770 Dec 15 '13 at 06:39
It's `java.math.BigDecimal` and `java.math.MathContext`. – Elliott Frisch Dec 15 '13 at 06:41
Oh, thanks, I copied and pasted ... not sure why it didn't pick those up. – user2962770 Dec 15 '13 at 06:45
You also missed `printf` instead of `println`. http://ideone.com/QJZRtY – Elliott Frisch Dec 15 '13 at 06:46

For loop, dividing one

4 Answers4