String to Boolean in Java

  1. Convert a String to boolean or Boolean Using Boolean.parseBoolean(string) in Java
  2. Convert a String to boolean or Boolean Using Boolean.valueOf(string) in Java
  3. Convert a String to boolean and Boolean Using BooleanUtils.toBoolean(string) in Java

Today, we will look at three methods that help us to convert a Java string to a boolean. We can use a boolean value with a primitive boolean or Boolean object. Although the Boolean class wraps the primitive boolean, we will see the cases of both in the following examples.

Convert a String to boolean or Boolean Using Boolean.parseBoolean(string) in Java

The first example uses the parseBoolean(string) method of the Boolean class. It directly parses or converts a given string to return a primitive boolean representing the string. One important thing to note is that this method will return false when a string value other than true or false is passed.

As we know that parseBoolean() returns a boolean, we can use the returned value as a boolean bool and Boolean boolObj because the Boolean class has the primitive boolean in it.

public class StringToBoolean {
    public static void main(String[] args) {
        String exampleString = "false";

        boolean bool = Boolean.parseBoolean(exampleString);
        Boolean boolObj = Boolean.parseBoolean(exampleString);

        System.out.println("Primitive boolean: " + bool);
        System.out.println("Boolean object: " + boolObj);
    }
}

Output:

Primitive boolean: false
Boolean object: false

Convert a String to boolean or Boolean Using Boolean.valueOf(string) in Java

Another static function of the Boolean class to convert a string to boolean is valueOf(). It takes the string as an argument and returns a Boolean value that represents the string. Below we can see that exampleString is initialized with true as a string, and we pass it to the valueOf(string) method.

public class StringToBoolean {
    public static void main(String[] args) {
        String exampleString = "true";

        boolean bool = Boolean.valueOf(exampleString);
        Boolean boolObj = Boolean.valueOf(exampleString);
        
        System.out.println("Primitive boolean: " + bool);
        System.out.println("Boolean object: " + boolObj);

    }
}

Output:

Primitive boolean: true
Boolean object: true

Convert a String to boolean and Boolean Using BooleanUtils.toBoolean(string) in Java

In both above methods, functions always return false if the string value is anything other than true or false. This issue can be solved using the BooleanUtils.toBoolean() method of the apache common library.

We use the following dependency in our project to include the library.

 <dependency>
     <groupId>org.apache.commons</groupId>
     <artifactId>commons-lang3</artifactId>
     <version>3.11</version>
 </dependency>

In the following example, we have three strings: yes, no, and true. And to convert all these values to a boolean, we will use BooleanUtils.toBoolean(string) and pass the string as an argument. In the output, we can see that all the values were parsed correctly. yes is converted to true, and no is converted to false.

import org.apache.commons.lang3.BooleanUtils;

public class StringToBoolean {
    public static void main(String[] args) {
        String exampleString = "yes";
        String exampleString1 = "no";
        String exampleString2 = "true";

        boolean bool1 = BooleanUtils.toBoolean(exampleString);
        Boolean boolObj1 = BooleanUtils.toBoolean(exampleString);

        boolean bool2 = BooleanUtils.toBoolean(exampleString1);
        Boolean boolObj2 = BooleanUtils.toBoolean(exampleString1);

        boolean bool3 = BooleanUtils.toBoolean(exampleString2);
        Boolean boolObj3 = BooleanUtils.toBoolean(exampleString2);

        System.out.println("Primitive boolean 1: " + bool1);
        System.out.println("Boolean object 1: " + boolObj1);

        System.out.println("Primitive boolean 2: " + bool2);
        System.out.println("Boolean object 2: " + boolObj2);

        System.out.println("Primitive boolean 3 : " + bool3);
        System.out.println("Boolean object 3: " + boolObj3);

    }
}

Output:

Primitive boolean 1: true
Boolean object 1: true
Primitive boolean 2: false
Boolean object 2: false
Primitive boolean 3 : true
Boolean object 3: true

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