Java OptionalLong equals()方法及示例

OptionalLong 帮助我们创建一个对象，该对象可能包含或不包含一个Long值。 equals(Object obj) 方法帮助我们比较这个OptionalLong对象和作为参数传递的对象，如果对象相等则返回true。

另一个对象被认为与这个OptionalLong对象相等，如果。

语法

public boolean equals(Object obj)

参数： 该方法接受一个 obj ，它是一个要进行平等测试的对象。

返回值： 如果其他对象 “等于 “该对象，该方法返回真，否则返回假。

下面的程序说明了equals(Object obj)方法。

程序1 :

// Java program to demonstrate// OptionalLong.equals(Object obj) method  import java.util.OptionalLong;  public class GFG {      public static void main(String[] args)    {          // Create first OptionalLong object        OptionalLong opLong1            = OptionalLong.of(45213246);          System.out.println("OptionalLong 1: "                           + opLong1.toString());          // Create second OptionalLong object        OptionalLong opLong2            = OptionalLong.of(45213246);          System.out.println("OptionalLong 2: "                           + opLong2.toString());          // Check if these two objects are equal        // using equals(Object obj)        System.out.println("Are both objects equal: "                           + opLong1.equals(opLong2));    }}

输出。

OptionalLong 1: OptionalLong[45213246]OptionalLong 2: OptionalLong[45213246]Are both objects equal: true

程序2

// Java program to demonstrate// OptionalLong.equals(Object obj) method  import java.util.OptionalLong;  public class GFG {      public static void main(String[] args)    {        // Create first OptionalLong object        OptionalLong opLong1            = OptionalLong.of(317946492);          System.out.println("OptionalLong 1: "                           + opLong1.toString());          // Create second OptionalLong object        OptionalLong opLong2            = OptionalLong.of(45213246);          System.out.println("OptionalLong 2: "                           + opLong2.toString());          // Check if these two objects are equal        // using equals(Object obj)        System.out.println("Are both objects equal: "                           + opLong1.equals(opLong2));    }}

输出。

OptionalLong 1: OptionalLong[317946492]OptionalLong 2: OptionalLong[45213246]Are both objects equal: false

**参考资料: ** https://docs.oracle.com/javase/10/docs/api/java/util/OptionalLong.html#equals? (Object obj)