字符串compareTo()方法 (String compareTo() Method)

compareTo() is a String method in Java and it is used to compare two strings (case-sensitive).

compareTo()是Java中的String方法，用于比较两个字符串(区分大小写)。

If both strings are equal – it returns 0, otherwise, it returns a value less than 0 or greater than 0 based on the first dissimilar characters difference.

如果两个字符串相等–返回0 ，否则，根据第一个不同的字符差返回小于0或大于0的值。

Syntax:

句法：

    int string1.compareTo(string2);

Here, string1 and string2 are the strings to be compared, and it returns an integer value that is 0, less than 0 or greater than 0.

在这里， string1和string2是要比较的字符串，它返回一个整数值，该值是0，小于0或大于0。

Example:

例：

    Input:
str1 = "Hello world!"
str2 = "Hello world!"
Output:
0
Input:
str1 = "Hello world!"
str2 = "HELLO WORLD!"
Output:
32

Java code to compare strings using String.compareTo() method

Java代码使用String.compareTo()方法比较字符串

public class Main
{public static void main(String[] args) {String str1 = "Hello world!";
String str2 = "Hello world!";
String str3 = "HELLO WORLD!";
System.out.println("str1.compareTo(str2) = " + str1.compareTo(str2));
System.out.println("str1.compareTo(str3) = " + str1.compareTo(str3));
System.out.println("str2.compareTo(str3) = " + str2.compareTo(str3));
//checking with the condition
if(str1.compareTo(str2)==0){System.out.println("str1 is equal to str2");
}
else{System.out.println("str1 is not equal to str2");
}
if(str1.compareTo(str3)==0){System.out.println("str1 is equal to str3");
}
else{System.out.println("str1 is not equal to str3");
}
if(str2.compareTo(str3)==0){System.out.println("str2 is equal to str3");
}
else{System.out.println("str2 is not equal to str3");
}
}
}

Output

输出量

str1.compareTo(str2) = 0
str1.compareTo(str3) = 32
str2.compareTo(str3) = 32
str1 is equal to str2
str1 is not equal to str3
str2 is not equal to str3

翻译自: https://www.includehelp.com/java/string-compareTo-method-with-example.aspx