Java Guava | Booleans.join() method with Examples

Last Updated : 11 Jul, 2025
The join() method of Booleans Class in the Guava library is used to combine or join all the given boolean values separated by a separator. These boolean values are passed a parameter to this method. This method also takes the separator as the parameter. This method returns a String which is the result of join operation on the specified boolean values. For example: join("-", false, true, false) returns the string "false-true-false". Syntax:
public static String join(String separator,
                          boolean... array)
Parameters: This method accepts two mandatory parameters:
  • separator: which is the character that occurs in between the joined boolean values
  • array: which is an array of boolean values that are to be joined.
Return Value: This method returns a string containing all the given boolean values separated by separator. Below programs illustrate the use of this method: Example-1 : Java
// Java code to show implementation of
// Guava's Booleans.join() method

import com.google.common.primitives.Booleans;
import java.util.Arrays;

class GFG {

    // Driver's code
    public static void main(String[] args)
    {
        // Creating a boolean array
        boolean[] arr = { true, false, true,
                          false, true };

        // Using Booleans.join() method to get a
        // string containing the elements of array
        // separated by a separator
        System.out.println(Booleans.join("#", arr));
    }
}
Output:
true#false#true#false#true
Example 2 : Java
// Java code to show implementation of
// Guava's Booleans.join() method

import com.google.common.primitives.Booleans;
import java.util.Arrays;

class GFG {

    // Driver's code
    public static void main(String[] args)
    {
        // Creating a boolean array
        boolean[] arr = { false, false,
                          true, false };

        // Using Booleans.join() method to get a
        // string containing the elements of array
        // separated by a separator
        System.out.println(Booleans.join("*", arr));
    }
}
Comment