Java类型转换/缩小原始变量

Question

I'm getting exponential value in the result of expression where I'm adding double with long.

package com.testing;

import java.util.Date;

public class TypeCasting {

    public static void main(String[] args) {
        long varA = 100000;
        long varB = 3000000;

        double logVarA = Math.log10(varA);      //  5.0
        double logVarB = Math.log10(varB);      // 6.477121254719663

        long timeStampInSec = new Date().getTime() / 1000;
        System.out.println(timeStampInSec);     // 1552543503

        double totalValue = logVarA + logVarB + timeStampInSec;
        System.out.println(totalValue);         // 1.5525435144771214E9

        double finalScoreDampingFactor = 1000;

        double finalScore = totalValue / finalScoreDampingFactor;
        System.out.println(finalScore);         // 1552543.5144771214   
    }

}

In totalValue variable why I'm getting 1.5525435144771214E9 value and when I'm deviding it with 1000, getting 1552543.5144771214 .

Can any body please explain ?

Answer 1

A number has the same value, regardless of how it's represented. What you see printed as a String is just a representation of the number.

The JVM has decided, for whichever reason, that the number should be printed in exponential form. If you want to force it to print it differently, you can use printf .

double totalValue = logVarA + logVarB + timeStampInSec;
System.out.printf("%f%n", totalValue);         // 1552547672.477121

Answer 2

1.5525435144771214E9 is 1552543514.... divided by 1000 is 1552543....

Is it possible that you misinterpreted the 1.5525435144771214E9 ?

Answer 3

The notation EX means "times 10 to the power of X".

So the original number was 1552543514.4771214 .