Java 番石榴| Booleans.toArray()方法带示例

原文:https://www . geesforgeks . org/Java-guava-booleans-to array-method-with-examples/

番石榴库中 布尔类toArray() 方法用于将作为参数传递给该方法的布尔值转换为布尔数组。这些布尔值作为集合传递给此方法。此方法返回一个布尔数组。

语法:

公共静态布尔[] toArray(集合<布尔>集合)

参数:该方法接受一个强制参数集合,该集合是要转换为布尔数组的布尔值的集合。

返回值:该方法返回一个布尔数组,该数组包含与集合相同的值,顺序相同。

异常:如果传递的集合或其任何元素为空,该方法将抛出 空指针异常

下面的程序说明了 toArray()方法的使用:

例 1:

// Java code to show implementation of
// Guava's Booleans.toArray() method

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

class GFG {

    // Driver's code
    public static void main(String[] args)
    {

        // Creating a List of Boolean
        List<Boolean> myList
            = Arrays.asList(false, true,
                            false, false);

        // Using Booleans.toArray() method to convert
        // a List or Set of Boolean to an array
        // of Boolean
        boolean[] arr = Booleans.toArray(myList);

        // Displaying an array containing each
        // value of collection,
        // converted to a boolean value
        System.out.println(Arrays.toString(arr));
    }
}

输出:

[false, true, false, false]

例 2:

// Java code to show implementation of
// Guava's Booleans.toArray() method

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

class GFG {

    // Driver's code
    public static void main(String[] args)
    {
        // Creating a List of Boolean
        List<Boolean> myList
            = Arrays.asList(true, true, false);

        // Using Booleans.toArray() method to convert
        // a List or Set of Boolean to an array
        // of Boolean
        boolean[] arr = Booleans.toArray(myList);

        // Displaying an array containing each
        // value of collection,
        // converted to a boolean value
        System.out.println(Arrays.toString(arr));
    }
}

输出:

[true, true, false]

参考:https://Google . github . io/guava/releases/20.0/API/docs/com/Google/common/primitive/booleans . html # to array-Java . util . collection-