# How to Find Square Root in Java

18 Nov 2019 12:39 pm || 0

## 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();
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``````

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