Float Wrapper Class in Java

The Float class wraps a value of primitive type float in an object. An object of type Float contains a single field whose type is a float.
In addition, this class provides several methods for converting a float to a String and a String to a float, as well as other constants and methods useful when dealing with a float.

Float class Constructors

  • Float(double value) - Constructs a newly allocated Float object that represents the argument converted to type float.
  • Float(float value) - Constructs a newly allocated Float object that represents the primitive float argument.
  • Float(String s) - Constructs a newly allocated Float object that represents the floating-point value of type float represented by the string.
Example:
float b = 55.05F;
String str = "45";
double d = 10.10;
// Construct three Float objects
Float x = new Float(b);
Float y = new Float(str);
Float z = new Float(d);

Float class Methods

The class diagram shows a list of APIs/Methods that Float class provides.
In this post, we will learn a few important methods of Float wrapper class.
Example: This program demonstrates usage of Float wrapper class methods.
package com.javaguides.corejava.wrapperclasses;

/**
 * This class to demonstrate Float wrapper class methods
 * @author javaguides.net
 *
 */
public class FloatClassExample {
 public static void main(String[] args) {
  float b = 55.05F;
  String str = "45";
  double d = 10.10;
  // Construct two Float objects
  Float x = new Float(b);
  Float y = new Float(str);

  // toString()
  System.out.println("toString(b) = " + Float.toString(b));

  // valueOf()
  // return Float object
  Float z = Float.valueOf(b);
  System.out.println("valueOf(b) = " + z);
  z = Float.valueOf(str);
  System.out.println("ValueOf(bb) = " + z);

  // parseFloat()
  // return primitive float value
  float zz = Float.parseFloat(str);
  System.out.println("parseFloat(bb) = " + zz);

  System.out.println("bytevalue(x) = " + x.byteValue());
  System.out.println("shortvalue(x) = " + x.shortValue());
  System.out.println("intvalue(x) = " + x.intValue());
  System.out.println("longvalue(x) = " + x.longValue());
  System.out.println("doublevalue(x) = " + x.doubleValue());
  System.out.println("floatvalue(x) = " + x.floatValue());

  int hash = x.hashCode();
  System.out.println("hashcode(x) = " + hash);

  boolean eq = x.equals(y);
  System.out.println("x.equals(y) = " + eq);

  int e = Float.compare(x, y);
  System.out.println("compare(x,y) = " + e);

  int f = x.compareTo(y);
  System.out.println("x.compareTo(y) = " + f);

  Float d = Float.valueOf("1010.54789654123654");
  System.out.println("isNaN(d) = " + d.isNaN());

  System.out.println("Float.isNaN(45.12452) = " + Float.isNaN(45.12452F));

  // Float.POSITIVE_INFINITY stores
  // the positive infinite value
  d = Float.valueOf(Float.POSITIVE_INFINITY + 1);
  System.out.println("Float.isInfinite(d) = " + Float.isInfinite(d.floatValue()));

  float dd = 10245.21452F;
  System.out.println("Float.toString(dd) = " + Float.toHexString(dd));

  int float_to_int = Float.floatToIntBits(dd);
  System.out.println("Float.floatToLongBits(dd) = " + float_to_int);

  float int_to_float = Float.intBitsToFloat(float_to_int);
  System.out.println("Float.intBitsToFloat(float_to_long) = " + int_to_float);
 }
}
Output:
toString(b) = 55.05
valueOf(b) = 55.05
ValueOf(bb) = 45.0
parseFloat(bb) = 45.0
bytevalue(x) = 55
shortvalue(x) = 55
intvalue(x) = 55
longvalue(x) = 55
doublevalue(x) = 55.04999923706055
floatvalue(x) = 55.05
hashcode(x) = 1113338675
x.equals(y) = false
compare(x,y) = 1
x.compareTo(y) = 1
isNaN(d) = false
Float.isNaN(45.12452) = false
Float.isInfinite(d) = true
Float.toString(dd) = 0x1.4029b8p13
Float.floatToLongBits(dd) = 1176507612
Float.intBitsToFloat(float_to_long) = 10245.215

References

https://docs.oracle.com/javase/8/docs/api/java/lang/Float.html

Related Wrapper Classes

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