The Boolean.valueOf()
method in Java is used to convert a String
or a boolean
primitive to a Boolean
object.
Table of Contents
- Introduction
valueOf()
Method Syntax- Overloaded
valueOf()
MethodsvalueOf(boolean b)
valueOf(String s)
- Examples
- Converting a
boolean
Primitive - Converting a
String
- Converting a
- Real-World Use Case
- Conclusion
Introduction
The Boolean.valueOf()
method is a static method in the Boolean
class in Java. It converts a boolean
primitive or a String
to a Boolean
object. This method is useful for converting values to Boolean
objects, which can be used in collections or other places where Boolean
objects are required.
valueOf()() Method Syntax
The syntax for the valueOf()
method is as follows:
valueOf(boolean b)
public static Boolean valueOf(boolean b)
- b: The boolean value to be converted to a
Boolean
object.
valueOf(String s)
public static Boolean valueOf(String s)
- s: The string to be converted to a
Boolean
object. If theString
is equal to "true" (ignoring case), the method returnsBoolean.TRUE
. For any other input, includingnull
, it returnsBoolean.FALSE
.
Overloaded valueOf()() Methods
valueOf(boolean b)
This method converts a boolean
primitive to a Boolean
object.
Example
public class ValueOfBooleanExample {
public static void main(String[] args) {
boolean boolPrimitive = true;
Boolean boolObject = Boolean.valueOf(boolPrimitive);
System.out.println("Boolean object: " + boolObject);
}
}
Output:
Boolean object: true
valueOf(String s)
This method converts a String
to a Boolean
object. If the String
is equal to "true" (ignoring case), it returns Boolean.TRUE
. For any other input, it returns Boolean.FALSE
.
Example
public class ValueOfStringExample {
public static void main(String[] args) {
String trueString = "true";
String falseString = "false";
String invalidString = "yes";
Boolean trueObject = Boolean.valueOf(trueString);
Boolean falseObject = Boolean.valueOf(falseString);
Boolean invalidObject = Boolean.valueOf(invalidString);
System.out.println("Boolean object (trueString): " + trueObject);
System.out.println("Boolean object (falseString): " + falseObject);
System.out.println("Boolean object (invalidString): " + invalidObject);
}
}
Output:
Boolean object (trueString): true
Boolean object (falseString): false
Boolean object (invalidString): false
Examples
Converting a boolean
Primitive
The valueOf(boolean b)
method can be used to convert a boolean
primitive to a Boolean
object.
Example
public class PrimitiveToBooleanExample {
public static void main(String[] args) {
boolean isAvailable = true;
Boolean isAvailableObject = Boolean.valueOf(isAvailable);
System.out.println("Boolean object: " + isAvailableObject);
}
}
Output:
Boolean object: true
Converting a String
The valueOf(String s)
method can be used to convert a String
to a Boolean
object.
Example
public class StringToBooleanExample {
public static void main(String[] args) {
String str = "true";
Boolean boolObject = Boolean.valueOf(str);
System.out.println("Boolean object: " + boolObject);
}
}
Output:
Boolean object: true
Handling Null Values
When passing null
to valueOf(String s)
, the method returns Boolean.FALSE
.
Example
public class NullStringExample {
public static void main(String[] args) {
String nullString = null;
Boolean boolObject = Boolean.valueOf(nullString);
System.out.println("Boolean object: " + boolObject);
}
}
Output:
Boolean object: false
Real-World Use Case
Storing Boolean Values in Collections
In a real-world scenario, you might need to store boolean values in a collection that requires Boolean
objects.
Example
import java.util.ArrayList;
import java.util.List;
public class BooleanCollectionExample {
public static void main(String[] args) {
List<Boolean> booleanList = new ArrayList<>();
boolean isCompleted = true;
String isAdmin = "false";
booleanList.add(Boolean.valueOf(isCompleted));
booleanList.add(Boolean.valueOf(isAdmin));
System.out.println("Boolean List: " + booleanList);
}
}
Output:
Boolean List: [true, false]
Parsing Configuration Settings
When reading configuration settings from a file or environment variables, you can use valueOf()
to convert string representations to Boolean
objects.
Example
public class ConfigExample {
public static void main(String[] args) {
String debugMode = System.getenv("DEBUG_MODE");
Boolean isDebugMode = Boolean.valueOf(debugMode);
if (isDebugMode) {
System.out.println("Debug mode is enabled.");
} else {
System.out.println("Debug mode is disabled.");
}
}
}
Output:
Debug mode is disabled.
(Assuming the DEBUG_MODE
environment variable is not set or is set to a value other than "true")
Conclusion
The Boolean.valueOf()
method in Java provides a convenient way to convert boolean
primitives and String
values to Boolean
objects. By understanding how to use this method and its overloaded variants, you can efficiently handle boolean conversions in your Java applications. Whether you are storing boolean values in collections, parsing configuration settings, or handling user input, the valueOf()
method provides a reliable solution for these tasks.