**java.lang.Math** class comes with many methods to do simple basic numeric operations. One such one is **sqrt()** method which returns the **square root** of a number passed as parameter.

One advantage of Math class methods is that they are declared as **static** so that they can be called without the need of object creation.

Following is the Math class signature as defined in java.lang package.

**public final class Math extends Object**

Following is the method signature as defined in Math class

**public static double sqrt(double a)**

This method takes a double value as parameter and returns a double value of the square root of the value passed as parameter.

- If the parameter passed is a negative value (below 0 value), the sqrt() function returns NaN (Not a Number).
- If the parameter is positive infinity, the result will be in positive infinity.
- If the parameter is negative infinity, the result will be in negative infinity.
- The same way with positive zero or negative zero.

###### Even a whole number is passed, the returned result will be a double value only. It is shown in the following example on "Find Square root of Number sqrt() Java".

```
public class MathFunctionDemo
{
public static void main(String args[])
{
int a = 25; // integer
double b = 25.5; // positive double value
int c = -25; // negative integer value
double d = -25.5; // negative double value
int e = 0; // positive zero value
int f = -0; // negative zero value
System.out.println("Square root of 25: " + Math.sqrt(a));
System.out.println("Square root of 25.5: " + Math.sqrt(b));
System.out.println("\nFollowing two square roots prints NaN as they are less than zero");
System.out.println("Square root of -25: " + Math.sqrt(c));
System.out.println("Square root of -25.5: " + Math.sqrt(d));
System.out.println("\nFollowing two square roots prints 0 as 0 is treated as neutral");
System.out.println("Square root of 0: " + Math.sqrt(e));
System.out.println("Square root of -0: " + Math.sqrt(f));
}
}
```

Output screenshot on Find Square root of Number sqrt() Java

If required a whole number, cast the result to int value as follows.

System.out.println("Square root of 25: " + (int) Math.sqrt(a));