Question

String s1 = "Project";
String s2 = "Sunject";

我想按字母顺序比较上面两个字符串（在本例中为“Project”，然后是“Sunject”，“P”在“S”之前）。有谁知道如何用Java做到这一点？

Answer 1

String.compareTo可能是也可能不是你需要的。

如果您需要字符串的本地化排序，请查看this链接。

Answer 2

查看String.compareTo方法。

s1.compareTo(s2)

来自javadocs：

结果是负整数if 这个String对象按字典顺序排列在参数字符串之前。该如果是这样，结果是正整数字符串对象按字典顺序排列跟随参数字符串。该如果字符串是，则结果为零等于; compareTo完全返回0 当equals（Object）方法会返回true。

Answer 3

String a = "..."; 
String b = "...";  

int compare = a.compareTo(b);  

if (compare < 0) {  
    //a is smaller
}
else if (compare > 0) {
    //a is larger 
}
else {  
    //a is equal to b
}

Answer 4

您可以调用string的compareTo方法（java.lang.String.compareTo）。此功能已有详细记录on the java documentation site。

这是一个演示它的简短程序：

class StringCompareExample {
    public static void main(String args[]){
        String s1 = "Project"; String s2 = "Sunject";
        verboseCompare(s1, s2);
        verboseCompare(s2, s1);
        verboseCompare(s1, s1);
    }

    public static void verboseCompare(String s1, String s2){
        System.out.println("Comparing \"" + s1 + "\" to \"" + s2 + "\"...");

        int comparisonResult = s1.compareTo(s2);
        System.out.println("The result of the comparison was " + comparisonResult);

        System.out.print("This means that \"" + s1 + "\" ");
        if(comparisonResult < 0){
            System.out.println("lexicographically precedes \"" + s2 + "\".");
        }else if(comparisonResult > 0){
            System.out.println("lexicographically follows \"" + s2 + "\".");
        }else{
            System.out.println("equals \"" + s2 + "\".");
        }
        System.out.println();
    }
}

这是一个现场演示，显示它有效：http://ideone.com/Drikp3

Answer 5

对于国有化后的字母顺序，请使用Collator。

//Get the Collator for US English and set its strength to PRIMARY
Collator usCollator = Collator.getInstance(Locale.US);
usCollator.setStrength(Collator.PRIMARY);
if( usCollator.compare("abc", "ABC") == 0 ) {
    System.out.println("Strings are equivalent");
}

有关支持的区域设置的列表，请参阅JDK 8 and JRE 8 Supported Locales。

Answer 6

import java.io.*;
import java.util.*;
public class CandidateCode {
    public static void main(String args[] ) throws Exception {
       Scanner sc = new Scanner(System.in);
           int n =Integer.parseInt(sc.nextLine());
           String arr[] = new String[n];
        for (int i = 0; i < arr.length; i++) {
                arr[i] = sc.nextLine();
                }


         for(int i = 0; i <arr.length; ++i) {
            for (int j = i + 1; j <arr.length; ++j) {
                if (arr[i].compareTo(arr[j]) > 0) {
                    String temp = arr[i];
                    arr[i] = arr[j];
                    arr[j] = temp;
                }
            }
        }
        for(int i = 0; i <arr.length; i++) {
            System.out.println(arr[i]);
        }
   }
}

Answer 7

    String s1 = "Project";
    String s2 = "Sunject";
    
    //print smaller one using compareTo() function
    if(s1.compareTo(s2)<0) System.out.println(s1);
    //if s1 is smaller then function returns negative which is less than 0 so s1 
    //is smaller
    else System.out.println(s2); // else s2 is smaller
    
    //print larger one using compareTo() function
    if(s1.compareTo(s2)>0) System.out.println(s1);
    //is s1 is larger function will give positive so print s1 else s2 
    else System.out.println(s2);

Answer 8

按照其他人的建议，您可以使用String.compareTo(String)。

但是，如果要对字符串列表进行排序，并且需要Comparator，则不必实现它，可以使用Comparator.naturalOrder()或Comparator.reverseOrder()。

按字母顺序比较字符串

8 个答案: