This article will provide a profound knowledge about how to round of numbers in java. In this write-up we will cover the below listed method to round of a number in java:
- What is Math.round() and how to use it in Java
- What is Math.ceil() and how to use it in Java
- What is Math.floor() and how to use it in Java
So, let’s get started!
What is Math.round() and how to use it in Java
It is a predefined method of Java’s Math class that cuts off the floating value and returns the closest integer-type number.
Example
This example will assist you to understand how to use the Math.round() method in java:
public static void main(String[] args) {
float number1 = 172.52f;
double number2 = 172.12;
float number3 = 10.12f;
float number4 = 10.72f;
double number5 = -570.82;
System.out.println("Rounding of 172.52: " + Math.round(number1));
System.out.println("Rounding of 172.12: " + Math.round(number2));
System.out.println("Rounding of 10.12: " + Math.round(number3));
System.out.println("Rounding of 10.72: " + Math.round(number4));
System.out.println("Rounding of -570.82: " + Math.round(number5));
}
}
Above program will produce the following output:
The output shows that the Math.round() method returned the closest integer number.
What is Math.ceil() and how to use it in Java
It is a predefined method of Java’s Math class that rounds the given number upward and returns the double-type value; the below-given example will provide you more clarity on this concept.
Example
We will modify the previous example and instead of Math.round() method we will utilize the Math.ceil() method:
public static void main(String[] args) {
float number1 = 172.52f;
double number2 = 172.12;
float number3 = 10.12f;
float number4 = 10.72f;
double number5 = -570.82;
System.out.println("Rounding of 172.52: " + Math.ceil(number1));
System.out.println("Rounding of 172.12: " + Math.ceil(number2));
System.out.println("Rounding of 10.12: " + Math.ceil(number3));
System.out.println("Rounding of 10.72: " + Math.ceil(number4));
System.out.println("Rounding of -570.82: " + Math.ceil(number5));
}
}
On successful execution of the program, we will get the following output:
The output shows that the Math.ceil() method returned upward nearest double-type values.
What is Math.floor() and how to use it in Java
This method opposes the concept of Math.ceil() method i.e. it rounds the given number downward and returns the double-type value.
Example
Let’s consider the below-given program to understand the working of the Math.floor() method.
public static void main(String[] args) {
float number1 = 172.52f;
double number2 = 172.12;
float number3 = 10.12f;
float number4 = 10.72f;
double number5 = -570.82;
System.out.println("Rounding of 172.52: " + Math.floor(number1));
System.out.println("Rounding of 172.12: " + Math.floor(number2));
System.out.println("Rounding of 10.12: " + Math.floor(number3));
System.out.println("Rounding of 10.72: " + Math.floor(number4));
System.out.println("Rounding of -570.82: " + Math.floor(number5));
}
}
On successful execution of the above given code, we will get the following output:
The output shows that the Math.floor() method returned the downward nearest double-type values.
Conclusion
The Math class provides three methods to round off a number i.e. round(), ceil(), floor(). The math.round() method cuts off the floating value and returns the closest integer-type number. The ceil() method rounds the given number upward and returns the double-type value while the floor() method rounds the given number downward and returns the double-type value. This write-up explained the working of three built-in methods to round off a number in java i.e. round(), ceil(), and floor().
