# Java Math class

In java, there is a rich set of mathematical methods/functions provided in the Java Math class. Some of common math method of Java are sqrt(), pow(), min), max(), floor(), round(), ceil(), random() etc. some of method or function called automatically by default.

In the following program I have provided some of the common Java Math class methods with comments and outputs.

public class MathLibraryExample

{

public static void main(String[] args)

{

double rint;

double x = 72.5;

double y = 79.7;

int i, j;

double a, b, c, num;

a = 5.2;

b = 5.9;

c = -5;

System.out.println("Math Function in Java");

System.out.println("=====================");

#### // Math.abs() will return absolute value(without any sign)

System.out.println(c + " Absolute value is " + Math.abs(c));

/*

#### Math.round() method returns the value in rounded form.

It will return the same value if the number is

below ½ or .5 otherwise it return the next higher integer value.

*/

System.out.println(x + " is approximately " + Math.round(x));

System.out.println(y + " is approximately " + Math.round(y));

/*The Math.ceil() return the rounded value to the

* next higher integer and it return double type value */

System.out.println("The ceiling of " + a + " is " + Math.ceil(a));

System.out.println("The ceiling of " + b + " is " + Math.ceil(b));

System.out.println("The ceiling of " + x + " is " + Math.ceil(x));

System.out.println("The ceiling of " + y + " is " + Math.ceil(y));

// Math.floor() returns a number down to the nearest integer

// it can round off a floating point number

System.out.println("The floor of " + a + " is " + Math.floor(a));

System.out.println("The floor of " + b + " is " + Math.floor(b));

System.out.println("The floor of " + x + " is " + Math.floor(x));

System.out.println("The floor of " + y + " is " + Math.floor(y));

// Math.rint() will returns the truncated value of the given number

// that is, the integer part of the value by removing fractional part

rint = 7.26;

System.out.println("The rint of " + rint + " is " + Math.rint(rint));

rint = 7.84;

System.out.println("The rint of " + rint + " is " + Math.rint(rint));

// Comparison operators

// min() returns the smaller of the two numbers.

// The value return's depending upon the number used as the

// arguments to the method

System.out.println("min(" + a + "," + b + ") is " + Math.min(a,b));

System.out.println("min(" + x + "," + y + ") is " + Math.min(x,y));

System.out.println("min(" + a + "," + b + ") is " + Math.min(a,b));

System.out.println("min(" + y + "," + b + ") is " + Math.min(y,b));

// There's a corresponding max() method

// that returns the larger of two numbers

// The value return's depending upon the number used as the

// arguments to the method

System.out.println("max(" + a + "," + b + ") is " + Math.max(a,b));

System.out.println("max(" + x + "," + y + ") is " + Math.max(x,y));

System.out.println("max(" + a + "," + x + ") is " + Math.max(a,x));

System.out.println("max(" + a + "," + b + ") is " + Math.max(a,b));

#### // The Math library Math.PI and Math.E defines

// constant value

System.out.println("Pi value is " + Math.PI);

System.out.println("e value is " + Math.E);

// Trigonometric methods in Java

// The arguments / parameters are given in radians

// Convert a 30 degree angle to radians

double angle = 30.0 * 2.0 * Math.PI/360.0;

System.out.println("cos(" + angle + ") is " + Math.cos(angle));

System.out.println("sin(" + angle + ") is " + Math.sin(angle));

#### // Inverse Trigonometric methods

// All values are returned as radians

double asine = Math.asin(sine);

double acosine = Math.acos(cosine);

double atan = Math.atan(tan);

System.out.println("The value Sine of       " + radians + " = " + sine);

System.out.println("The value Cosine of     " + radians + " = " + cosine);

System.out.println("The value Tangent of    " + radians + " = " + tan);

System.out.println("The value Arcsine of    " + sine + " = " + asine);

System.out.println("The value Arccosine of  " + cosine + " = " + acosine);

System.out.println("The value Arctangent of " + tan + " = " + atan);

#### // Exponential and Logarithmic Methods in java

// Math.exp(2.0) returns e (7.38905609893065) raised

// to the power of a.

System.out.println("exp(2.0) is " + Math.exp(2.0));

System.out.println("exp(10.0) is " + Math.exp(10.0));

System.out.println("exp(0.0) is " + Math.exp(0.0));

// Math.log(a) returns the natural

// logarithm (base e) of a.

System.out.println("log(2.0) is " + Math.log(1.0));

System.out.println("log(10.0) is " + Math.log(10.0));

System.out.println("log(Math.E) is " + Math.log(Math.E));

#### // math.pow() method in java

// Math.pow(x, y) returns the x raised

// to the yth power.

System.out.println("pow(10, 3) is " + Math.pow(10,3));

System.out.println("pow(5.0, 4.5) is " + Math.pow(5.0,4.5));

System.out.println("pow(10, -1) is " + Math.pow(10,-1));

#### // Math.sqrt(num) returns the square root of num

num = 25;

System.out.println("The square root of " +  num + " is " + Math.sqrt(num));

// Math.cbrt() return the cube root of number

num = 125;

System.out.println("The cube root of " +  num + " is " + Math.cbrt(num));

#### // Random method Math.random() in java

// will return pseudo-random number between 0.0 and 1.0;

System.out.println("Random number genetated  : " + Math.random());

System.out.println("Here's 5 random number is: " + Math.random()*5);

}

}

Output

Math Function in Java

=====================

-5.0 Absolute value is 72.5

72.5 is approximately 73

79.7 is approximately 80

The ceiling of 5.2 is 6.0

The ceiling of 5.9 is 6.0

The ceiling of 72.5 is 73.0

The ceiling of 79.7 is 80.0

The floor of 5.2 is 5.0

The floor of 5.9 is 5.0

The floor of 72.5 is 72.0

The floor of 79.7 is 79.0

The rint of 7.26 is 7.0

The rint of 7.84 is 8.0

min(5.2,5.9) is 5.2

min(72.5,79.7) is 72.5

min(5.2,5.9) is 5.2

min(79.7,5.9) is 5.9

max(5.2,5.9) is 5.9

max(72.5,79.7) is 79.7

max(5.2,72.5) is 72.5

max(5.2,5.9) is 5.9

Pi value is 3.141592653589793

e value is 2.718281828459045

cos(0.5235987755982988) is 0.8660254037844387

sin(0.5235987755982988) is 0.49999999999999994

The value Sine of       1.5 = 0.9974949866040544

The value Cosine of     1.5 = 0.0707372016677029

The value Tangent of    1.5 = 14.101419947171719

The value Arcsine of    0.9974949866040544 = 1.5000000000000002

The value Arccosine of  0.0707372016677029 = 1.5

The value Arctangent of 14.101419947171719 = 1.5

exp(2.0) is 7.38905609893065

exp(10.0) is 22026.465794806718

exp(0.0) is 1.0

log(2.0) is 0.0

log(10.0) is 2.302585092994046

log(Math.E) is 1.0

pow(10, 3) is 1000.0

pow(5.0, 4.5) is 1397.5424859373686

pow(10, -1) is 0.1

The square root of 25.0 is 5.0

The cube root of 125.0 is 5.0

Random number genetated  : 0.2738161073495178

Here's 5 random number is: 2.1900603338270512

More Java program

# Prime Adam Number In Java

A positive integer without leading zeros is prime (a number which has only two factors) and its reverse integer is also prime.

The square of a prime number and the square of its reverse is the same to each other is known as

Example:

If number = 13 and reverse of number = 31, then,

(13)2 <13*13>= 169   Square of the number

(31)2 <31*31>= 961 which is reverse of 169. Which is the same as 13^2 = 169 so 13 is a prime adam number.

import java.util.*;

{

/*

*If n=13 and reverse of "n" =31, then,

*(13)^2 = 169

*(31)^2 =961 which is the reverse of 169

*/

int i, rev, num, digit;  // rev=reverse,i is for loop

boolean prime;

{

rev = 0;

prime = true;

}

int reverse(int n)

{

num = n;

rev = 0;

while(num!=0)

{

digit = num%10;

rev = rev*10 + digit;

num = num/10;

}

return rev;

}

{

num = n;

for(i=2; i<num; i++)

{

if(num%i == 0)

{

prime = false;

break;

}

}

return prime;

}

// Main method

public static void main(String args[])

{

int number, rev, sq1, sq2, revsq;

boolean isPrime1, isPrime2;

Scanner sc = new Scanner(System.in);

System.out.println("Enter number to Check prime Adam Integer :");

number = sc.nextInt();

// Call the reverse function

rev = ob.reverse(number);

sq1 = number * number;

sq2 = rev * rev;

revsq = ob.reverse(sq2);

System.out.println(sq1);

System.out.println(sq2);

System.out.println(revsq);

if((isPrime1==true && isPrime2==true) && sq1 == revsq)

{

System.out.println("Entered number is Prime Adam Integer");

}

else

{

System.out.println("Entered number is Not Prime Adam Integer");

}

}

}

• In the above program, we have taken a number say number=13
• That 13 passes to the reverse(number) method and it return 31
• Next square the number 13*13 and the rev 31*31 of the number.
• Next reverse the 31*31 and the result is 169.
• Now both number is the same then that number is Prime Adam Number

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