Java整数 compareTo() 方法

Java.lang包Integer类的compareTo()方法对两个Integer对象进行数值比较，如果这个Integer等于参数Integer则返回值0；如果此 Integer 在数值上小于参数 Integer，则值小于 0；如果此 Integer 在数值上大于参数 Integer（有符号比较），则值大于 0。

句法 ：

public int compareTo(Integer anotherInt)
Parameter :
anotherInt- : the Integer to be compared.
Return :
- This method returns the value 0 if this Integer is 
equal to the argument Integer; 
- a value less than 0 if this Integer is 
numerically less than the argument Integer; 
- and a value greater than 0 if this Integer is
numerically greater than the argument Integer
(signed comparison).

示例：显示Java.lang.Integer.compareTo()方法的工作。

// Java program to demonstrate working
// of java.lang.Integer.compareTo() method
import java.lang.Integer;
  
class Gfg {
  
    // driver code
    public static void main(String args[])
    {
        Integer a = new Integer(10);
        Integer b = new Integer(20);
  
        // as 10 less than 20, Output will be a value less than zero
        System.out.println(a.compareTo(b));
  
        Integer x = new Integer(30);
        Integer y = new Integer(30);
  
        // as 30 equals 30, Output will be zero
        System.out.println(x.compareTo(y));
  
        Integer w = new Integer(15);
        Integer z = new Integer(8);
  
        // as 15 is greater than 8, Output will be a value greater than zero
        System.out.println(w.compareTo(z));
    }
}

输出：

-1
0
1