How to Find Square Root in Java

Find Square Root in Java

To find out the square root of any number in you can use the following methods:

• Using Math.sqrt() Function
• Using Custom Function
• Without using any function

1) Java Math.sqrt() Function

The math.sqrt() function is an in-built function in Java, which returns the square root of a double value argument. 

Notes:

• If the input argument is NaN (Not a Number) or negative than the return value will be NaN
• If the input argument is positive infinity, then the return value will also be positive infinity.
• If the input argument is positive zero, then the return value will be positive zero.
• If the input argument is negative zero, then the return value will be negative zero.

Syntax

public static double sqrt(double arg)

Parameter

The math.sqrt() function takes only one parameter which is:

• arg: an argument whose square root has to be taken.

Return Value

This math.sqrt() function returns square root of a double value argument

Java program to find the square root of a number using math.sqrt()

//Java program to find the square root of a number

//Simple Program (With inbuilt function)

//Importing Scanner Class of util package
import java.util.Scanner;
//Importing Math Class of lang package
import java.lang.Math;

//Main Class of the program
public class Main
{
    //Main method of the program
    public static void main(String[] args) {
        //Giving hint to the user for, What to enter
        System.out.print("Please enter the number : ");
        //Creating the object of Scanner Class
        Scanner input = new Scanner(System.in);
        //Taking input from user
        float number_1 = input.nextFloat();
        //Printing the output
        System.out.println("Square root of "+ number_1+ " is: "+Math.sqrt(number_1));
    }
}

OUTPUT:

Please enter the number: 30
Square root of 30.0 is: 5.477225575051661

2) Square Root in Java Using Custom Function

//Java program to find the square root of a number

//Simple Program (Using Custom Function)

//Importing Scanner Class of util package
import java.util.Scanner;

//Main Class of the program
public class Main
{
  //Custom method to find square root
  public static double findSquareRoot(float number){
    double number_2 = number / 2;
    double temp;
    do
        {
          temp = number_2;
          number_2 = (temp + (number / temp)) / 2;
        }while ((temp-number_2) != 0 );

    //Returning the result

    return number_2;

  }
    //Main method of the program
    public static void main(String[] args) {
        //Giving hint to the user for, What to enter
        System.out.print("Please enter the number : ");
        //Creating the object of Scanner Class
        Scanner input = new Scanner(System.in);
        //Taking input from user
        float number_1 = input.nextFloat();
        //Printing the result
        System.out.println("Square root of "+ number_1+ " is: "+findSquareRoot(number_1));
    }
} 

Output

Please enter the number: 30
Square root of 30.0 is: 5.477225575051661

3) Square Root in Java without using Math.sqrt() Function

//Java program to find the square root of a number

//Simple Program (Without inbuilt function)

//Importing Scanner Class of util package
import java.util.Scanner;

//Main Class of the program
public class Main
{
    //Main method of the program
    public static void main(String[] args) {
        //Giving hint to the user for, What to enter
        System.out.print("Please enter the number : ");
        //Creating the object of Scanner Class
        Scanner input = new Scanner(System.in);
        //Taking input from user
        float number_1 = input.nextFloat();
        //Login Start
        double number_2 = number_1 / 2;
        double temp;
        do
        {
          temp = number_2;
          number_2 = (temp + (number_1 / temp)) / 2;
        }while ((temp-number_2) != 0 );
        //Logic Ends
        System.out.println("Square root of "+ number_1+ " is: "+number_2);
    }
}

Output:

Please enter the number: 30
Square root of 30.0 is: 5.477225575051661