Java SortedMap equals()用法及代碼示例

Java SortedMap中的equals()方法用於檢查兩個SortedMap實例之間的相等性。它驗證作為參數傳遞的一個SortedMap的元素是否等於此SortedMap的元素。

用法:

boolean equals(object obj)

參數：該方法接受此映射類型的一個參數obj，表示要與該映射檢查其相等性的映射。

返回值：如果兩個對象映射都相等，則該方法返回true，否則返回false。

注意：SortedMap中的equals()方法是從Java中的Map接口繼承的。

以下示例程序旨在說明equals()方法：

示例1:

// Java code to illustrate 
// the equals() method 
  
import java.util.*; 
  
public class Map_Demo { 
    public static void main(String[] args) 
    { 
  
        // Creating an empty SortedMap 
        SortedMap<Integer, String> map1 
            = new TreeMap<Integer, String>(); 
        SortedMap<Integer, String> map2 
            = new TreeMap<Integer, String>(); 
  
        // 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)); 
    } 
}

輸出：

First Map:
 {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You}
Second Map:
 {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You}
Equality: true

示例2:

// Java code to illustrate 
// the equals() method 
  
import java.util.*; 
  
public class Map_Demo { 
    public static void main(String[] args) 
    { 
  
        // Creating an empty SortedMap 
        SortedMap<Integer, String> map1 
            = new TreeMap<Integer, String>(); 
        SortedMap<Integer, String> map2 
            = new TreeMap<Integer, String>(); 
  
        // Mapping string values 
        // to int keys for map1 
        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 for map2 
        map2.put(10, "Geeks"); 
        map2.put(15, "4"); 
        map2.put(20, "Geek"); 
        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)); 
    } 
}

輸出：

First Map: {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You}
Second Map: {10=Geeks, 15=4, 20=Geek, 25=Welcomes, 30=You}
Equality: false

參考： https://docs.oracle.com/javase/7/docs/api/java/util/Map.html#equals(java.lang.Object)

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注：本文由純淨天空篩選整理自gopaldave大神的英文原創作品 SortedMap equals() method in Java with Examples。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。