Java exp Function

The Java exp Function is one of the Math functions, which is useful to return E raised to the power of double value. Where E is Euler’s number, and it is approximately equal to 2.71828.

Java exp Function Syntax

The basic syntax of the Math.exp in Java Programming language is as shown below.

static double exp(double number); //Return Type is Double

// In order to use in program: 
Math.exp(double number);

Number: It can be a double value or a valid numerical expression, and it represents the exponent value.

If the number argument is a positive or negative double value, the Math.exp function will return the output.
If the number argument is not a number, the Java Math.exp function will return NaN.
When the number argument is positive infinity, the Math.exp function will return Positive Infinity as the output.
If it is negative infinity, the Math.exp function will return Positive Zero as output.

For example, if we specify the expression as Java Math.exp (2.00). It means e² ==> 2.718² ==> 7.38

Java exp Function Example

In this program, we use the Java Math.exp Function to calculate the power of Euler’s number E of both positive and negative values and display the output.

package MathFunctions;

public class ExpMethod {
	public static void main(String[] args) {
		double a = Math.exp(10.9666 - 14.9865 + 10.9852);
		System.out.println("Math.Exp Result = = " + a);	

		System.out.println("\nMath.Exp Result of Positive Number = " + Math.exp(4.25));
		System.out.println("Math.Exp Result of Positive Number = " + Math.exp(6.95));
		
		System.out.println("\nMath.Exp Result of Negative Number = " + Math.exp(-2.85));
		System.out.println("Math.Exp Result of Negative Number = " + Math.exp(-10.25));
		
		System.out.println("\nMath.Exp Result = " + Math.exp(1));
		System.out.println("Math.Exp Result = " + Math.exp(-1));
	}
}

First, we declared a variable of type Double and performed the Math.exp function directly on the expression.

double a = Math.exp(10.9666 - 14.9865 + 10.9852);
System.out.println("Math.Exp Result = = " + a);

Next, we used the Java Math.exp Function directly on Positive double values. Here, Math.exp(4.25) means (2.71828)^4.25

System.out.println("\nMath.Exp Result of Positive Number = " + Math.exp(4.25));
System.out.println("Math.Exp Result of Positive Number = " + Math.exp(6.95));

Here, we used the Function directly on Negative double values.

System.out.println("\nMath.Exp Result of Negative Number = " + Math.exp(-2.85));
System.out.println("Math.Exp Result of Negative Number = " + Math.exp(-10.25));

Next, we used the Math.exp Function directly on both Positive and Negative double values.

System.out.println("\nMath.Exp Result = " + Math.exp(1));
System.out.println("Math.Exp Result = " + Math.exp(-1));

Java exp on Array example

In this Java program, we return the Euler’s number E raised by the power of bulk data. Here, we are going to declare an array of double type and use the Java Math.exp function of array elements.

package MathFunctions;

public class ExpMethodOnArrays {
	public static void main(String[] args) {
		
		double [] myArray = {-1.69, 5.98, 4.21, -3.9999, 6.879, 4.4897};

		for (int i = 0; i < myArray.length; i++) {
			System.out.format("Math.Exp Result of Array Element = %.2f\n", Math.exp(myArray[i]));
		}
	}
}

Math.Exp Result of Array Element = 0.18
Math.Exp Result of Array Element = 395.44
Math.Exp Result of Array Element = 67.36
Math.Exp Result of Array Element = 0.02
Math.Exp Result of Array Element = 971.65
Math.Exp Result of Array Element = 89.09

We used the For Loop to iterate the Array. Within the exp For Loop, we initialized the i value as 0. Next, the compiler will check for the condition (i < myArray.length). As along the condition is True statement inside the for loop will be executed.

TIP: myArray.length finds the length of the Java array.

for (int i = 0; i < myArray.length; i++) {

Here, we used the exp Math function directly inside the System.out.format statement. Here, the compiler will call the Math.exp method ( static double exp(double number) ) to find the corresponding exp value and print the output.

System.out.format("Math.Exp Result of Array Element = %.2f\n", Math.exp(myArray[i]));

NOTE: To use Math.exp on a single item, then use: Math.exp(myArray[index_position])

Java exp function on Arraylist example

In this Java program, we are going to declare an arraylist of double type and return the Euler’s number E raised by the power of list elements.

package MathFunctions;

import java.util.ArrayList;

public class ExpMethodOnArrayList {
	public static void main(String[] args) {
		
		ArrayList<Double> myList = new ArrayList<Double>(5);
		myList.add(-2.5);
		myList.add(2.5);
		myList.add(4.25);
		myList.add(-4.25);
		myList.add(5.00);
		
		for (double x : myList) {
			System.out.println("Math.Exp Result of ArrayList =  " + Math.exp(x));
		}
	}
}

Math.Exp Result of ArrayList =  0.0820849986238988
Math.Exp Result of ArrayList =  12.182493960703473
Math.Exp Result of ArrayList =  70.10541234668786
Math.Exp Result of ArrayList =  0.014264233908999256
Math.Exp Result of ArrayList =  148.4131591025766

We used the For Loop to iterate the double values in ArrayList

for (double x : myList) {

Here, the compiler will call the ( static double exp(double x) method to find the corresponding exp value and print the output.

System.out.println("Math.Exp Result of ArrayList =  " + Math.exp(x));