Boolean functions in java

Class Boolean

The 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 .

In addition, this class provides many methods for converting a boolean to a String and a String to a boolean , as well as other constants and methods useful when dealing with a boolean .

This is a value-based class; programmers should treat instances that are equal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail.

Field Summary

Constructor Summary

Method Summary

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.

Returns true if and only if the system property named by the argument exists and is equal to, ignoring case, the string «true» .

Methods declared in class java.lang.Object

Field Details

TRUE

FALSE

TYPE

Constructor Details

Boolean

It is rarely appropriate to use this constructor. The static factory valueOf(boolean) is generally a better choice, as it is likely to yield significantly better space and time performance. Also consider using the final fields TRUE and FALSE if possible.

Boolean

It is rarely appropriate to use this constructor. Use parseBoolean(String) to convert a string to a boolean primitive, or use valueOf(String) to convert a string to a Boolean object.

Allocates a Boolean object representing the value true if the string argument is not null and is equal, ignoring case, to the string «true» . Otherwise, allocates a Boolean object representing the value false .

Method Details

parseBoolean

Parses the string argument as a boolean. The boolean returned represents the value true if the string argument is not null and is equal, ignoring case, to the string «true» . Otherwise, a false value is returned, including for a null argument. Example: Boolean.parseBoolean(«True») returns true .
Example: Boolean.parseBoolean(«yes») returns false .

booleanValue

valueOf

Returns a Boolean instance representing the specified boolean value. If the specified boolean value is true , this method returns Boolean.TRUE ; if it is false , this method returns Boolean.FALSE . If a new Boolean instance is not required, this method should generally be used in preference to the constructor Boolean(boolean) , as this method is likely to yield significantly better space and time performance.

valueOf

Returns a Boolean with a value represented by the specified string. The Boolean returned represents a true value if the string argument is not null and is equal, ignoring case, to the string «true» . Otherwise, a false value is returned, including for a null argument.

toString

Returns a String object representing the specified boolean. If the specified boolean is true , then the string «true» will be returned, otherwise the string «false» will be returned.

toString

Returns a String object representing this Boolean’s value. If this object represents the value true , a string equal to «true» is returned. Otherwise, a string equal to «false» is returned.

hashCode

hashCode

equals

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.

getBoolean

Returns true if and only if the system property named by the argument exists and is equal to, ignoring case, the string «true» . A system property is accessible through getProperty , a method defined by the System class. If there is no property with the specified name, or if the specified name is empty or null, then false is returned.

compareTo

compare

Boolean.valueOf(x).compareTo(Boolean.valueOf(y))

logicalAnd

logicalOr

logicalXor

describeConstable

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Boolean functions in java

The 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 . In addition, this class provides many methods for converting a boolean to a String and a String to a boolean , as well as other constants and methods useful when dealing with a boolean .

Field Summary

Constructor Summary

Allocates a Boolean object representing the value true if the string argument is not null and is equal, ignoring case, to the string «true» .

Method Summary

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.

Returns true if and only if the system property named by the argument exists and is equal to the string «true» .

Methods inherited from class java.lang.Object

Field Detail

TRUE

FALSE

TYPE

Constructor Detail

Boolean

public Boolean(boolean value)

Allocates a Boolean object representing the value argument. Note: It is rarely appropriate to use this constructor. Unless a new instance is required, the static factory valueOf(boolean) is generally a better choice. It is likely to yield significantly better space and time performance.

Boolean

Allocates a Boolean object representing the value true if the string argument is not null and is equal, ignoring case, to the string «true» . Otherwise, allocate a Boolean object representing the value false . Examples: new Boolean(«True») produces a Boolean object that represents true .
new Boolean(«yes») produces a Boolean object that represents false .

Method Detail

parseBoolean

Parses the string argument as a boolean. The boolean returned represents the value true if the string argument is not null and is equal, ignoring case, to the string «true» . Example: Boolean.parseBoolean(«True») returns true .
Example: Boolean.parseBoolean(«yes») returns false .

booleanValue

public boolean booleanValue()

valueOf

Returns a Boolean instance representing the specified boolean value. If the specified boolean value is true , this method returns Boolean.TRUE ; if it is false , this method returns Boolean.FALSE . If a new Boolean instance is not required, this method should generally be used in preference to the constructor Boolean(boolean) , as this method is likely to yield significantly better space and time performance.

valueOf

Returns a Boolean with a value represented by the specified string. The Boolean returned represents a true value if the string argument is not null and is equal, ignoring case, to the string «true» .

toString

Returns a String object representing the specified boolean. If the specified boolean is true , then the string «true» will be returned, otherwise the string «false» will be returned.

toString

Returns a String object representing this Boolean’s value. If this object represents the value true , a string equal to «true» is returned. Otherwise, a string equal to «false» is returned.

hashCode

hashCode

public static int hashCode(boolean value)

equals

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.

getBoolean

Returns true if and only if the system property named by the argument exists and is equal to the string «true» . (Beginning with version 1.0.2 of the Java TM platform, the test of this string is case insensitive.) A system property is accessible through getProperty , a method defined by the System class. If there is no property with the specified name, or if the specified name is empty or null, then false is returned.

compareTo

compare

public static int compare(boolean x, boolean y)

Boolean.valueOf(x).compareTo(Boolean.valueOf(y))

logicalAnd

public static boolean logicalAnd(boolean a, boolean b)

logicalOr

public static boolean logicalOr(boolean a, boolean b)

logicalXor

public static boolean logicalXor(boolean a, boolean b)

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How to Return a Boolean Method in Java

In Java, you can declare a method using the void keyword or with primitive data types. The keyword is used when you do not want to return anything from the method. However, if you return an integer type value, then declare the method with the int keyword. Similarly, “boolean” is also a primitive data type in Java, and it is used to declare a method when you want to return a boolean value.

This blog will explain the procedure to return a boolean method in Java.

How to Return a Boolean Method in Java?

As we discussed earlier, the return type of method is mentioned in the method declaration. If a method is declared with a boolean return type, it gives a boolean value.

Syntax
Follow the syntax for returning a boolean method in Java.

Here, “abc()” is a boolean method that returns the boolean value “false”.

Now, let’s head toward the implementation of the Boolean method in Java.

Example 1: Implementing a Simple Boolean Method

We will create a boolean method named “value()” that contains a boolean variable “a” with the value “true”. The return statement of this method will be a boolean as the method is declared as a boolean type:

We will call the boolean method value() in the main() method to print out the returned value:

The output displayed the “true” as the returned value:

Let’s see how the boolean method works with conditional statements.

Example 2: Adding if-else Conditional Statement in Boolean Method

Here, we will create a boolean method named “isGreater()” with an integer type parameter “num”. If num is greater than “50”, the method will return “true” else “false”:

public static boolean isGreater ( int num ) {
if ( num > 50 ) {
return true ;
}
else {
return false ;
}
}

We will call the isGreater() method by passing a number “85” in main() method, and check if the returned value is equals to true, then it will print “True”, else display “False”:

public static void main ( String [ ] args ) {
if ( isGreater ( 85 ) == true ) {
System. out . println ( «True» ) ;
} else {
System. out . println ( «False» ) ;
}

Output

Look at one more example to understand the concept.

Example 3: Checking If a Number is Odd or Even Using Boolean Method

First, we will create a boolean method named “isOdd()” that returns the boolean value true or false. The statement “return (num % 2 != 0)” will return true, if the result is not equals to 0, otherwise it returns false:

Now, in the main() method, we will create an integer type variable named “number” assigned with value “89”. The “isOdd()” method will accept the created integer as an argument. The given method will print out the specified statements according to the evaluation of the given condition:

public static void main ( String [ ] args ) {
int number = 89 ;
if ( isOdd ( number ) == true ) {
System. out . print ( «89 is an odd Number» ) ;
} else {
System. out . print ( «89 is an even Number» ) ; }
}

The output shows “True” as the isOdd() method returned true:

We gathered all the instructions to return a boolean method in Java.

Conclusion

In Java, you must declare a method of the boolean type in order for it to return a boolean value. The boolean method will return the boolean value, true or false. You can either return the variable containing a boolean value or use conditional statements to decide the returned value. In this blog, we explained the procedure to return a boolean method in Java with detailed examples.

About the author

Farah Batool

I completed my master’s degree in computer science. I am an academic researcher and love to learn and write about new technologies. I am passionate about writing and sharing my experience with the world.

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