How to round integer in java

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I want to round the number 1732 to the nearest ten, hundred and thousand. I tried with Math round functions, but it was written only for float and double. How to do this for Integer? Is there any function in java?

Use Precision (Apache Commons Math 3.1.1)

Precision.round(double, scale); // return double
Precision.round(float, scale); // return float

Use MathUtils (Apache Commons Math) - Older versions

MathUtils.round(double, scale); // return double
MathUtils.round(float, scale); // return float

scale - The number of digits to the right of the decimal point. (+/-)


Discarded because method round(float, scale) be used.

Math.round(MathUtils.round(1732, -1)); // nearest ten, 1730 Math.round(MathUtils.round(1732, -2)); // nearest hundred, 1700 Math.round(MathUtils.round(1732, -3)); // nearest thousand, 2000


Better solution

int i = 1732;
MathUtils.round((double) i, -1); // nearest ten, 1730.0
MathUtils.round((double) i, -2); // nearest hundred, 1700.0
MathUtils.round((double) i, -3); // nearest thousand, 2000.0

Java Math round() method with Example, Use Precision (Apache Commons Math 3.1.1) Precision.round(double, scale); // return double Precision.round(float, scale); // return float. The method round returns the closest long or int, as given by the methods return type. Syntax. This method has the following variants − long round(double d) int round(float f) Parameters. Here is the detail of parameters − d − A double or float primitive data type. f − A float primitive data type. Return Value

What rounding mechanism do you want to use? Here's a primitive approach, for positive numbers:

int roundedNumber = (number + 500) / 1000 * 1000;

This will bring something like 1499 to 1000 and 1500 to 2000.

If you could have negative numbers:

int offset = (number >= 0) ? 500 : -500;
int roundedNumber = (number + offset) / 1000 * 1000;

How to round integer in java, There is a Math class in the package java.lang, which contains 3 methods of rounding of numbers with a floating point to the nearest integer: 1. Java does a round down in case of division of two integer numbers. 6. Dividing two integers to double in Java? As we saw in the previous section dividing two integers and getting the result in a integer variable, leads to a Round to zero behaviour. if you need a double result of the division type cast first the operands to a double type.

(int)(Math.round( 1732 / 10.0) * 10)

Math.round(double) takes the double and then rounds up as an nearest integer. So, 1732 will become 173.2 (input parameter) on processing by Math.round(1732 / 10.0). So the method rounds it like 173.0. Then multiplying it with 10 (Math.round( 1732 / 10.0) * 10) gives the rounded down answer, which is 173.0 will then be casted to int.

Rounding of Numbers in Java • Vertex Academy, However, both types should never be used for precise values, such as currencies​. For that, and also for rounding, we can use the BigDecimal  The java.lang.Math.round(float a) returns the closest int to the argument. The result is rounded to an integer by adding 1/2, taking the floor of the result, and casting the result to type int. Special cases −

You could try:

int y = 1732;
int x = y - y % 10;

The result will be 1730.

Edit: This doesn't answer the question. It simply removes part of the number but doesn't "round to the nearest".

How to Round a Number to N Decimal Places in Java, MIN_VALUE, this method will return Integer.MIN_VALUE. If the argument is negative Infinity or any value less than or equal to the value of Long.​MAX_VALUE, this  @MuhammedRefaat, Math.round(double) takes the double and then rounds up as an integer. So, 1732 will become 173.2 on processing by Math.round(). So the method rounds it like 173.0. Then multiplying it with 10 gives the rounded down answer.

At nearest ten:

int i = 1986;
int result;

result = i%10 > 5 ? ((i/10)*10)+10 : (i/10)*10;

(Add zero's at will for hundred and thousand).

Java Math.round() method with Examples, 5, INT, then divide back. Whatever Java has stolen from .NET, for some reason Math.round still only gives you an integer, and there is no overload with a digit  Math.round() Method Another way of rounding numbers is to use Math.Round() Method. In this case, we can control n number of decimal places by multiplying and dividing by 10^n :

How to round a decimal to nearest integer in Java, So Does Java division round down? The answer is Yes. Java does a round down in case of division of two integer numbers. 6. Dividing two  When you run the program, the output will be: In the above program, we've used format () method to print the given floating point number num to 4 decimal places. The 4 decimal places is given by the format .4f. This means, print only upto 4 places after the dot (decimal places), and f means to print the floating point number.

Rounding Number in Java, Java - round() Method - The method round returns the closest long or int, as given by the methods return type. The round() method rounds a number to the nearest integer. Note: 2.49 will be rounded down (2), and 2.5 will be rounded up (3).

Java - round() Method, Suppose you have a double primitive variable 4.444 and you want to convert it to the integer value 4, how do you that in Java? Since double is  int a = (int) Math.round(doubleVar); This will round it and cast it to an int. The simplest method you get taught in most basic computer science classes is probably to add 0.5 (or subtract it, if your double is below 0) and simply cast it to int.

Comments
  • Your chosen answer is edited.
  • How can I do that for the nearest 12?
  • this here is the right approach: int r = ((int)((n + 500) / 1000)) * 1000 since only the casting to int cuts off the digits
  • there is not type defined in your approach for "number"! so it makes ALL sense my friend.
  • "number" is an integer. Read the original question again.
  • I think 10D is what you mean instead of 10L. Isn't it? +1
  • well, it works but you are better explain how your answer works
  • @MuhammedRefaat, Math.round(double) takes the double and then rounds up as an integer. So, 1732 will become 173.2 on processing by Math.round(). So the method rounds it like 173.0. Then multiplying it with 10 gives the rounded down answer.
  • @Sibidharan thanks for the explanation, my comment was to make the people who see his post understand why his code solves the problem, you can edit the answer with your explanation.
  • 1736 would also go to 1730, which wouldn't be the nearest ten.
  • ...and the result for 1739 will also be 1730. Not most people's expectation for rounding.
  • @cherouvim: Well, at least you're still scoring all the upvotes :)