Java - Coding Challenge 5 - Decimal Comparator

gistfile1.txt

// numbers must be equal up to 3 decimal places

public class DecimalComparator {

    public static boolean areEqualByThreeDecimalPlaces(double first,double second) {

        if (first <0 && second >0 || first >0 && second <0){
            return false;
        }

        double firstThousand = first*1000;
        double secondThousand = second*1000;

        int firstint = (int)firstThousand;
        int secondint = (int)secondThousand;

        if (firstint==secondint){
            return true;
        }

        return false;

    }

}

why is the double being multiple to 1000?

for be comparable, instead of compare those decimal numbers you compare 2 int numbers, if you look line 14 he use casting

 public static boolean areEqualByThreeDecimalPlaces(double first, double second) {

 if (first <0 && second >0 || first >0 && second <0){
                return false;
            }


// you can cast directly without using second pair or double
        int i = (int)(first*1000);  
            int j = (int)(second*1000);

            if(i==j){
                return true;
            }
            return false;
   }

Can some body explainme about this

package edu.fcc.cmis.decimalcomparator;

public class DecimalComparator {

// Write your 3 methods here






// Use the main method to test your code (optional)
public static void main(String[] args) {

// System.out.println(sameIntegralPart(22.34, 22.37867)); // true
// System.out.println(sameIntegralPart(141457105122.34667, 141457105111.34667)); // false
//
// System.out.println(areEqualWithinPrecision(-1341.235, -1341.23534667, 3)); // true
// System.out.println(areEqualWithinPrecision(1341.2357, 1341.235346, 4)); // false
// System.out.println(areEqualWithinPrecision(0.2357, 0.235346, 4)); // false
//
// System.out.println(areEqualWithinPrecision(0.2357, 0.235346)); // true
}
}

Footer

It needs to return true if two double numbers are the same up to three decimal places. Otherwise, returns false.