Java 简明教程

Java - Boolean class

Java Boolean Class

Java Boolean 类将基本类型 boolean 的值封装在一个对象中。类型为 Boolean 的对象包含一个字段，其类型为 boolean。

The Java Boolean class wraps a value of the primitive type boolean in an object. An object of type Boolean contains a single field whose type is boolean.

Boolean Class Declaration in Java

以下是*java.lang.Boolean* 类的声明：

Following is the declaration for java.lang.Boolean class −

public final class Boolean
   extends Object
      implements Serializable, Comparable<Boolean>

Boolean Class Fields

以下是*java.lang.Boolean* 类的字段：

Following are the fields for java.lang.Boolean class −

static Boolean FALSE − This is the Boolean object corresponding to the primitive value false.
static Boolean TRUE − This is the Boolean object corresponding to the primitive value true.
static Class<Boolean> TYPE − This is the Class object representing the primitive type boolean.

Boolean Class Constructors

Sr.No.

Constructor & Description

Boolean(boolean value) This allocates a Boolean object representing the value argument.

Boolean(String s) This allocates a Boolean object representing the value true if the string argument is not null and is equal, ignoring case, to the string "true".

Boolean Class Methods

Sr.No.	Method & Description
1	boolean booleanValue()This method returns the value of this Boolean object as a boolean primitive.
2	int compareTo(Boolean b)This method compares this Boolean instance with another.
3	boolean equals(Object obj)This method returns true if and only if the argument is not null and is a Boolean object that represents the same boolean value as this object.
4	static boolean getBoolean(String name)This method returns true if and only if the system property named by the argument exists and is equal to the string "true".
5	int hashCode()This method returns a hash code for this Boolean object.
6	int hashCode(boolean value)This method returns a hash code for a given boolean value. It is compatible with Boolean.hashCode().
7	static boolean logicalAnd(boolean a, boolean b)This method returns the result of applying the logical AND operator to the specified boolean operands.
8	static boolean logicalOr(boolean a, boolean b)This method returns the result of applying the logical OR operator to the specified boolean operands.
9	static boolean logicalXor(boolean a, boolean b)This method returns the result of applying the logical XOR operator to the specified boolean operands.
10	static boolean parseBoolean(String s)This method parses the string argument as a boolean.
11	String toString()This method returns a String object representing this Boolean’s value.
12	static String toString(boolean b)This method returns a String object representing the specified boolean.
13	static Boolean valueOf(boolean b)This method returns a Boolean instance representing the specified boolean value.
14	static Boolean valueOf(String s)This method returns a Boolean with a value represented by the specified string.

Methods Inherited

此类从以下类中继承方法：

This class inherits methods from the following classes −

java.lang.Object

Example of Java Boolean Class

以下示例展示了 Boolean 类提供的一些重要方法的使用。

The following example shows the usage of some important methods provided by Boolean class.

package com.tutorialspoint;
public class BooleanDemo {
   public static void main(String[] args) {

      // create 2 Boolean objects b1, b2
      Boolean b1, b2;

      // assign values to b1, b2
      b1 = Boolean.valueOf(true);
      b2 = Boolean.valueOf(false);

      // create an int res
      int res;

      // compare b1 with b2
      res = b1.compareTo(b2);

      String str1 = "Both values are equal ";
      String str2 = "Object value is true";
      String str3 = "Argument value is true";
      if( res == 0 ) {
      	System.out.println( str1 );
      } else if( res > 0 ) {
         System.out.println( str2 );
      } else if( res < 0 ) {
         System.out.println( str3 );
      }
   }
}

Output

让我们编译并运行上述程序，这将生成以下结果 −

Let us compile and run the above program, this will produce the following result −

Object value is true