Java中的属性 equals(value) 方法及示例

Properties 类的equals(value)方法用于检查两个属性之间的相等性。它验证作为参数传递的一个属性对象的元素是否等于该属性的元素。

句法：

public boolean equals(Object value)

参数：此方法接受此属性类型的参数值，并引用要与此映射检查其相等性的映射。

返回：此方法返回一个布尔值，说明两个对象属性是否相等。

下面的程序说明了 equals(value) 方法：

方案一：

// Java program to demonstrate
// equals(value) method.
  
import java.util.*;
  
public class GFG {
  
    // Main method
    public static void main(String[] args)
    {
  
        // Create a properties and add some values
        Properties properties = new Properties();
        properties.put("Pen", 10);
        properties.put("Book", 500);
        properties.put("Clothes", 400);
        properties.put("Mobile", 5000);
  
        // Print Properties details
        System.out.println("Properties 1: "
                           + properties.toString());
  
        // Create another properties and add some values
        Properties properties1 = new Properties();
        properties1.put("Pen", 10);
        properties1.put("Book", 500);
        properties1.put("Clothes", 400);
        properties1.put("Mobile", 5000);
  
        // Print Properties details
        System.out.println("Properties 2: "
                           + properties1.toString());
  
        // Checking the equality
        System.out.println("Are both properties equal: "
                           + properties.equals(properties1));
    }
}

输出：

Properties 1: {Book=500, Mobile=5000, Pen=10, Clothes=400}
Properties 2: {Book=500, Mobile=5000, Pen=10, Clothes=400}
Are both properties equal: true

方案二：

// Java program to demonstrate
// equals(value) method.
  
import java.util.*;
  
public class GFG {
  
    // Main method
    public static void main(String[] args)
    {
  
        // Create a properties and add some values
        Properties properties = new Properties();
  
        properties.put(1, "100RS");
        properties.put(2, "500RS");
        properties.put(3, "1000RS");
  
        // Print Properties details
        System.out.println("Current Properties: "
                           + properties.toString());
  
        // Create another properties and add some values
        Properties properties1 = new Properties();
        properties1.put("Pen", 10);
        properties1.put("Book", 500);
        properties1.put("Clothes", 400);
        properties1.put("Mobile", 5000);
  
        // Print Properties details
        System.out.println("Properties 2: "
                           + properties1.toString());
  
        // Checking the equality
        System.out.println("Are both properties equal: "
                           + properties.equals(properties1));
    }
}

输出：

Current Properties: {3=1000RS, 2=500RS, 1=100RS}
Properties 2: {Book=500, Mobile=5000, Pen=10, Clothes=400}
Are both properties equal: false

参考资料：https://docs.oracle.com/javase/9/docs/api/ Java/util/Properties.html#equals-java.lang.Object-