Java中的 Collator compare(String, String) 方法与示例

Java.text.Collator类的compare()方法用于比较两个字符串的强度，并根据结果返回 0、正负值作为输出。

句法：

public abstract int compare(String source,
                            String target)

参数：此方法采用两个字符串，将在它们之间进行比较。
返回值：如果第一个字符串等于、大于或小于另一个字符串，则它将分别返回零、正和负值。

以下是说明compare()方法的示例：

示例 1：

Java

// Java program to demonstrate
// compare() method
 
import java.text.*;
import java.util.*;
import java.io.*;
 
public class GFG {
    public static void main(String[] argv)
    {
        try {
 
            // Creating and initializing Collator Object
            Collator col = Collator.getInstance();
 
            // Creating an initializing object for comparison
            String obj1 = "ab";
 
            // Creating an initializing Object for comparison
            String obj2 = "Ab";
 
            // compare both object
            // using compare() method
            int i = col.compare(obj1, obj2);
 
            // display result
            if (i < 0)
                System.out.println("ab is less than Ab");
            else if (i > 0)
                System.out.println("ab is greater than Ab");
            else
                System.out.println("ab is equal to Ab");
        }
 
        catch (ClassCastException e) {
 
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

ab is less than Ab

示例 2：

Java

// Java program to demonstrate
// compare() method
 
import java.text.*;
import java.util.*;
import java.io.*;
 
public class GFG {
    public static void main(String[] argv)
    {
        try {
 
            // Creating and initializing Collator Object
            Collator col = Collator.getInstance();
 
            // Creating an initializing object for comparison
            String obj1 = "ab";
 
            // Creating an initializing Object for comparison
            String obj2 = "cd";
 
            // compare both object
            // using compare() method
            int i = col.compare(obj1, obj2);
 
            // display result
            if (i < 0)
                System.out.println("ab is less than cd");
            else if (i > 0)
                System.out.println("ab is greater than cd");
            else
                System.out.println("ab is equal to cd");
        }
 
        catch (ClassCastException e) {
 
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

ab is less than cd

参考： https://docs.oracle.com/javase/9/docs/api/ Java/text/Collator.html#compare-java.lang.String-java.lang.String-