The abs() Method in Java

Mehvish Ashiq Apr 01, 2022

We will learn about the `abs()` method in Java to find the absolute value of a specified number. We will be learning by writing and practicing various code examples.

What Is the Absolute Value in Java

Absolute value means a non-negative value of the specified number. For instance, the absolute value of -4 is 4.

We use the `abs()` method of the `java.lang.Math` package. It takes only one argument of type `int`, `double`, `float`, or `long` and returns its non-negative (absolute) value.

The following are some rules of thumb that you must remember to be an expert while finding an absolute value of a given number.

1. If the argument’s data type is `float` or `double`:
1.1 The `abs()` returns the positive value; it does not matter if the passed argument is positive or negative.
1.2 It results as `POSITIVE_INFINITY` if we pass `Infinity` as an argument.
1.3 It returns `NaN` if its argument is `NaN`.
1.4 It returns a positive zero if the `abs()` method gets a negative or positive zero.
2. If the argument’s data type is `long` or `int`:
2.1 If the value of `Long.MIN_VALUE` or `Integer.MIN_VALUE` is equal to the `abs()` method’s argument, the output would be the same, a negative value.

Use the `abs()` Method to Find the Absolute Value of a Number in Java

In this section, we will be writing different code examples to practice all the rules that are given above.

Example Code (when a negative number is passed as an argument):

``````import java.lang.Math;

public class findAbsoluteValue {
public static void main(String[] args){

int intNumber = -8;
System.out.println("Before applying the Math.abs() function: "+intNumber);

int absoluteValue = Math.abs(intNumber);
System.out.println("After applying the Math.abs() function: " + absoluteValue);

}
}
``````

Output:

``````Before applying the Math.abs() function: -8
After applying the Math.abs() function: 8
``````

Inside the `main` method, we declare and initialize a variable to hold a value further passed to the `Math.abs()` function to calculate a given number’s absolute value (positive value).

We print the value of a number before and after applying the `Math.abs()` function. This same process will be followed in the upcoming examples, but the variable name and type will be changed.

Example Code (when a positive number is passed as an argument):

``````import java.lang.Math;

public class findAbsoluteValue {
public static void main(String[] args){

int intNumber = 8;
System.out.println("Before applying the Math.abs() function: "+intNumber);

int absoluteValue = Math.abs(intNumber);
System.out.println("After applying the Math.abs() function: " + absoluteValue);

}
}
``````

Output:

``````Before applying the Math.abs() function: 8
After applying the Math.abs() function: 8
``````

Example Code (when `infinity` is passed as an argument):

``````import java.lang.Math;

public class findAbsoluteValue {
public static void main(String[] args){

double doubleNumber = Double.POSITIVE_INFINITY;
System.out.println("Before applying the Math.abs() function: "+doubleNumber);

double absoluteValue = Math.abs(doubleNumber);
System.out.println("After applying the Math.abs() function: " + absoluteValue);

}
}
``````

Output:

``````Before applying the Math.abs() function: Infinity
After applying the Math.abs() function: Infinity
``````

Example Code (when `NaN` is passed as an argument):

``````import java.lang.Math;

public class findAbsoluteValue {
public static void main(String[] args){

double doubleNumber = Double.NaN;
System.out.println("Before applying the Math.abs() function: "+doubleNumber);

double absoluteValue = Math.abs(doubleNumber);
System.out.println("After applying the Math.abs() function: " + absoluteValue);

}
}
``````

Output:

``````Before applying the Math.abs() function: NaN
After applying the Math.abs() function: NaN
``````

Example Code (when positive zero or negative zero is passed as an argument):

``````import java.lang.Math;

public class findAbsoluteValue {
public static void main(String[] args){

int number, absoluteValue;

number = -0;
System.out.println("Before applying the Math.abs() function: "+number);
absoluteValue = Math.abs(number);
System.out.println("After applying the Math.abs() function: " + absoluteValue);

number = 0;
System.out.println("Before applying the Math.abs() function: "+number);
absoluteValue = Math.abs(number);
System.out.println("After applying the Math.abs() function: " + absoluteValue);

}
}
``````

Output:

``````Before applying the Math.abs() function: 0
After applying the Math.abs() function: 0
Before applying the Math.abs() function: 0
After applying the Math.abs() function: 0
``````

Example Code (when `Long.MIN_VALUE` or `Integer.MIN_VALUE` is passed as an argument):

``````import java.lang.Math;

public class findAbsoluteValue {
public static void main(String[] args){

long longNumber = Long.MIN_VALUE;
System.out.println("Before applying the Math.abs() function: "+longNumber);
long longAbsVal = Math.abs(longNumber);
System.out.println("After applying the Math.abs() function: " + longAbsVal);

int intNumber = Integer.MIN_VALUE;
System.out.println("Before applying the Math.abs() function: "+intNumber);
int intAbsVal = Math.abs(intNumber);
System.out.println("After applying the Math.abs() function: " + intAbsVal);

}
}
``````

Output:

``````Before applying the Math.abs() function: -9223372036854775808
After applying the Math.abs() function: -9223372036854775808
Before applying the Math.abs() function: -2147483648
After applying the Math.abs() function: -2147483648
``````

Mehvish Ashiq is a former Java Programmer and a Data Science enthusiast who leverages her expertise to help others to learn and grow by creating interesting, useful, and reader-friendly content in Computer Programming, Data Science, and Technology.