用示例映射Java中的 equals() 方法
Java中的Java .util.Map.equals() 方法用于检查两个映射之间的相等性。它验证作为参数传递的一个映射的元素是否等于该映射的元素。
句法:
boolean equals(object obj)
参数:该方法接受一个此映射类型的参数obj ,并引用要与此映射检查其相等性的映射。
返回值:如果相等对两个对象映射都成立,则该方法返回 true,否则返回 false。
下面的程序说明了Java.util.Map.equals() 方法:
方案一:
// Java code to illustrate the equals() method
import java.util.*;
public class Map_Demo {
public static void main(String[] args)
{
// Creating an empty Map
Map map1 = new HashMap();
Map map2 = new HashMap();
// Mapping string values to int keys
map1.put(10, "Geeks");
map1.put(15, "4");
map1.put(20, "Geeks");
map1.put(25, "Welcomes");
map1.put(30, "You");
// Mapping string values to int keys
map2.put(10, "Geeks");
map2.put(15, "4");
map2.put(20, "Geeks");
map2.put(25, "Welcomes");
map2.put(30, "You");
// Displaying the Map1
System.out.println("First Map: "
+ map1);
// Displaying the Map2
System.out.println("Second Map: "
+ map2);
// Checking the equality
System.out.println("Equality: " + map1.equals(map2));
}
}
输出:
First Map: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4}
Second Map: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4}
Equality: true
方案二:
// Java code to illustrate the equals() method
import java.util.*;
public class Map_Demo {
public static void main(String[] args)
{
// Creating an empty Map
Map map1 = new HashMap();
Map map2 = new HashMap();
// Mapping string values to int keys for map1
map1.put(10, "Geeks");
map1.put(15, "four");
map1.put(20, "Geeks");
map1.put(25, "Welcomes");
map1.put(30, "You");
// Mapping string values to int keys for map2
map2.put(10, "Geeks");
map2.put(15, "4");
map2.put(20, "Geeks");
map2.put(25, "Welcomes");
map2.put(30, "You");
// Displaying the map 1
System.out.println("First Map: " + map1);
// Displaying the map 2
System.out.println("Second Map: " + map2);
// Displaying the equality
System.out.println("Equality: " + map1.equals(map2));
}
}
输出:
First Map: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=four}
Second Map: {20=Geek, 25=Welcomes, 10=Geeks, 30=You, 15=4}
Equality: false
参考:https: Java Java.lang.Object)