Double and Float
- These are the wrappers for floating point values double and float.
- The constructors for Float are
Float(double num) //constructs Float object for type double
Float(float num) //constructs Float object for type float
Float(String str) throws NumberFormatException //constructs Float object for type String contains floating point number.
The constructors for Double are
Double(double num) //constructs Double object from double type value
Double(String str) throws NumberFormatException//constructs Double object from String contains floating point number.
//example for creating Double
public class DoubleDemo
{
public static void main(String args[])
{
Double d1 = new Double(3.14159);
Double d2 = new Double("314159E-5");
System.out.println(d1 + " = " + d2 + " -> " + d1.equals(d2));
}
}
Output:
3.14159 = 3.14159 –> true
- Both Float and Double define the following constants:
Methods defined by Float are :
// Demonstrate isInfinite() and isNaN()
public class FloatDemo
{
public static void main(String args[])
{
Float f1=new Float(1.23);
Float f2=new Float(1.2);
System.out.println("byte byteValue( ) "+f1.byteValue()); //returns byte value for a Float object
System.out.println("static int compare(float num1, float num2) "+Float.compare(f2,f1)); //compares two float values
System.out.println("int compareTo(Float f ) "+f1.compareTo(f2)); //compares the invoking float object to another object
System.out.println("double doubleValue( ) "+f1.doubleValue()); //returns the double value of the object
System.out.println("boolean equals(Object FloatObj) "+f1.equals(f2)); //checks for equality of one object to another
float f11=f1.floatValue();
System.out.println("float floatValue( )"+f11); //returns the float value of the object
System.out.println("int hashCode( ) "+f1.hashCode()); //returns the hashcode for the invoking object
System.out.println("static int hashCode(float num) "+ Float.hashCode(f11)); //returns the hashcode for the float number
System.out.println("static float intBitsToFloat(int num) "+Float.intBitsToFloat(7));//converts the integer value to the float object value
System.out.println("int intValue( ) "+f1.intValue( )); //returns the integer value for the object
System.out.println("long longValue( ) "+f1.longValue()); //returns the long value for the object
System.out.println("static float max(float val, float val2) "+Float.max(f1,f2)); //returns the value of the float variable having maximum value
System.out.println("static float min(float val, float val2) "+Float.min(f1,f2)); //returns the minimum value among the two float values
System.out.println("short shortValue( ) "+f1.shortValue()); //returns the shortValue for a Float object
System.out.println("static float sum(float val, float val2) "+Float.sum(f1,f2)); //returns the sum of the two float objects
System.out.println("String toString( ) "+f1.toString()); //returns the corresponding string object to the Float object
System.out.println("static String toString(float num) "+Float.toString(f1));//returns the string format for the corresponding object
System.out.println("static Float valueOf(float num) "+Float.valueOf(f11));//returns the float object containg the value of num
}
}
Output:
byte byteValue( ) 1
static int compare(float num1, float num2) -1
int compareTo(Float f ) 1
double doubleValue( ) 1.2300000190734863
boolean equals(Object FloatObj) false
float floatValue( )1.23
int hashCode( ) 1067282596
static int hashCode(float num) 1067282596
static float intBitsToFloat(int num) 9.8E-45
int intValue( ) 1
long longValue( ) 1
static float max(float val, float val2) 1.23
static float min(float val, float val2) 1.2
short shortValue( ) 1
static float sum(float val, float val2) 2.43
String toString( ) 1.23
static String toString(float num) 1.23
static Float valueOf(float num) 1.23
Methods defined by Double are:
// Demonstrate isInfinite() and isNaN()
public class FloatDemo
{
public static void main(String args[])
{
Double d1=new Double(1.23433);
Double d2=new Double(1.2045);
System.out.println("byte byteValue( ) "+d1.byteValue()); //returns byte value for a Double object
System.out.println("static int compare(double num1, double num2) "+Double.compare(d2,d1)); //compares two double values
System.out.println("int compareTo(Dopuble d) "+d1.compareTo(d2)); //compares the invoking Double object to another object
System.out.println("double doubleValue( ) "+d1.doubleValue()); //returns the double value of the object
System.out.println("boolean equals(DoubleObj)) "+d1.equals(d2)); //checks for equality of one object to another
float f11=d1.floatValue();
System.out.println("float floatValue( )"+f11); //returns the float value of the object
System.out.println("int hashCode( ) "+d1.hashCode()); //returns the hashcode for the invoking object
System.out.println("static int hashCode(double num) "+ Double.hashCode(d1)); //returns the hashcode for the float number
System.out.println("static float intBitsToFloat(int num) "+Float.intBitsToFloat(7));//converts the integer value to the float object value
System.out.println("int intValue( ) "+d1.intValue( )); //returns the integer value for the object
System.out.println("long longValue( ) "+d1.longValue()); //returns the long value for the object
System.out.println("static double max(double val, double val2) "+Double.max(d1,d2)); //returns the value of the double variable having maximum value
System.out.println("static double min(double val, double val2) "+Double.min(d1,d2)); //returns the minimum value among the two double values
System.out.println("short shortValue( ) "+d1.shortValue()); //returns the shortValue for a Double object
System.out.println("static double sum(double val, double val2) "+Double.sum(d1,d2)); //returns the sum of the two double objects
System.out.println("String toString( ) "+d1.toString()); //returns the corresponding string object to the Double object
System.out.println("static String toString(double num) "+Double.toString(d1));//returns the string format for the corresponding object
System.out.println("static Float valueOf(double num) "+Double.valueOf(d1));//returns the double object containg the value of num
}
}
Output:
byte byteValue( ) 1
static int compare(double num1, double num2) -1
int compareTo(Dopuble d) 1
double doubleValue( ) 1.23433
boolean equals(DoubleObj)) false
float floatValue( )1.23433
int hashCode( ) -275500080
static int hashCode(double num) -275500080
static float intBitsToFloat(int num) 9.8E-45
int intValue( ) 1
long longValue( ) 1
static double max(double val, double val2) 1.23433
static double min(double val, double val2) 1.2045
short shortValue( ) 1
static double sum(double val, double val2) 2.43883
String toString( ) 1.23433
static String toString(double num) 1.23433
static Float valueOf(double num) 1.23433
isInfinite( ) and isNaN( )
- These are the methods provided by the both Float and Double.
- These methods are used to test for two unique values.
isInfinite( ) returns trueif the value being tested is infinitely large or small in magnitude.
isNaN( )returns true if the value being tested is not a number
// Demonstrate isInfinite() and isNaN()
public class InfNaN
{
public static void main(String args[])
{
Double d1 = new Double(1/0.);
Double d2 = new Double(0/0.);
System.out.println(d1 + ": " + d1.isInfinite() + ", " + d1.isNaN());
System.out.println(d2 + ": " + d2.isInfinite() + ", " + d2.isNaN());
}
}
Output:
Infinity: true, false
NaN: false, true