Convert double to Int, rounded down

Question

How to convert a double value to int doing the following:

Double If x = 4.97542. Convert to int x = 4.

Double If x = 4.23544. Convert to int x = 4.

That is, the answer is always rounding down.

score 106 · Accepted Answer · edited Oct 01 '17 at 04:58

106

If you explicitly cast double to int, the decimal part will be truncated. For example:

int x = (int) 4.97542;   //gives 4 only
int x = (int) 4.23544;   //gives 4 only

Moreover, you may also use Math.floor() method to round values in case you want double value in return.

edited Oct 01 '17 at 04:58

Code-Apprentice

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answered Apr 23 '12 at 12:29

waqaslam

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What does it mean to "loose decimal values"? Does it give the same numbers as calling `Math.floor()`? – Samuel Edwin Ward Dec 27 '15 at 00:17
A Double is not an Integer, so the cast won't work. Note the difference between the Double class and the double primitive. Also note that a Double is a Number, so it has the method intValue, which you can use to get the value as a primitive int. If you try to cast Double to int you will get a casting exception: java.lang.ClassCastException: java.lang.Double cannot be cast to java.lang.Integer – Ali Rad Feb 28 '19 at 14:22

Natix · Answer 2 · 2013-05-06T21:31:20.420

31

If the double is a Double with capital D (a boxed primitive value):

Double d = 4.97542;
int i = (int) d.doubleValue();

// or directly:
int i2 = d.intValue();

If the double is already a primitive double, then you simply cast it:

double d = 4.97542;
int i = (int) d;

edited May 06 '13 at 21:31

answered Apr 23 '12 at 12:34

Natix

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can you please tell me what is the difference between Double and double ? – Muhammed Refaat Apr 27 '14 at 07:48
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a double is a primitive float point value. A Double is a Java Object. – penguin Nov 03 '15 at 21:23

score 5 · Answer 3 · answered Apr 23 '12 at 12:32

5

double myDouble = 420.5;
//Type cast double to int
int i = (int)myDouble;
System.out.println(i);

The double value is 420.5 and the application prints out the integer value of 420

answered Apr 23 '12 at 12:32

Habib

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score 3 · Answer 4 · answered Nov 20 '15 at 13:46

3

Another option either using Double or double is use Double.valueOf(double d).intValue();. Simple and clean

answered Nov 20 '15 at 13:46

Joao Evangelista

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score 0 · Answer 5 · edited Nov 07 '15 at 21:57

I think I had a better output, especially for a double datatype sorting.

Though this question has been marked answered, perhaps this will help someone else;

Arrays.sort(newTag, new Comparator<String[]>() {
         @Override
         public int compare(final String[] entry1, final String[] entry2) {
              final Integer time1 = (int)Integer.valueOf((int) Double.parseDouble(entry1[2]));
              final Integer time2 = (int)Integer.valueOf((int) Double.parseDouble(entry2[2]));
              return time1.compareTo(time2);
         }
    });

Convert double to Int, rounded down

5 Answers5

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