Java Double.compareTo()用法及代码示例

java.lang.Double.compareTo()是java中的内置方法，该方法以数字方式比较两个Double对象。如果此对象等于自变量对象，则此方法返回0；如果此对象在数值上小于自变量对象，则返回小于0；如果此对象在数值上大于自变量对象，则返回大于0的值。

用法:

public int compareTo(Object obj)

参数：该方法接受一个参数。
对象–要比较的对象。

返回值：该函数可以返回三个值：

等于0：对象等于参数对象
小于0：对象小于参数对象
大于0：对象大于参数对象

以下示例程序旨在说明java.lang.Double.compareTo()方法的用法：

示例1:当两个对象都不相同时。

// Java program to demonstrate 
// of java.lang.Double.compareTo() method 
import java.lang.Math; 
  
class Gfg1 { 
  
    // Driver code 
    public static void main(String args[]) 
    { 
  
        // When two objects are different 
        Double obj1 = new Double(124); 
        Double obj2 = new Double(167); 
        int compareValue = obj1.compareTo(obj2); 
  
        if (compareValue == 0) 
            System.out.println("object1 and object2 are equal"); 
        else if (compareValue < 0) 
            System.out.println("object1 is less than object2"); 
        else
            System.out.println("object1 is greater than object2"); 
    } 
}

输出：

object1 is less than object2

示例2:没有传递任何参数时。

// Java program to demonstrate 
// of java.lang.Double.compareTo() method 
import java.lang.Math; 
  
class Gfg1 { 
  
    // Driver code 
    public static void main(String args[]) 
    { 
        // When no argument is passed 
        Double obj1 = new Double(124); 
        Double obj2 = new Double(167); 
  
        int compareValue = obj1.compareTo(); 
  
        if (compareValue == 0) 
            System.out.println("object1 and object2 are equal"); 
        else if (compareValue < 0) 
            System.out.println("object1 is less than object2"); 
        else
            System.out.println("object1 is greater than object2"); 
    } 
}

输出：

prog.java:14: error: method compareTo in class Double 
cannot be applied to given types;
        int compareValue = obj1.compareTo();
                               ^
  required: Double
  found: no arguments
  reason: actual and formal argument lists differ in length
1 error

示例3:除了对象以外的任何东西都作为参数传递时。

// Java program to demonstrate 
// of java.lang.Double.compareTo() method 
import java.lang.Math; 
  
class Gfg1 { 
  
    // Driver code 
    public static void main(String args[]) 
    { 
  
        // When anything other than object 
        // argument is passed 
        Double obj1 = new Double(124); 
  
        int compareValue = obj1.compareTo("gfg"); 
  
        if (compareValue == 0) 
            System.out.println("object1 and object2 are equal"); 
        else if (compareValue < 0) 
            System.out.println("object1 is less than object2"); 
        else
            System.out.println("object1 is greater than object2"); 
    } 
}

输出：

prog.java:15: error: incompatible types: String cannot be converted to Double
        int compareValue = obj1.compareTo("gfg");
                                          ^
Note: Some messages have been simplified; recompile with 
-Xdiags:verbose to get full output
1 error

相关用法

注：本文由纯净天空筛选整理自Twinkl Bajaj大神的英文原创作品 Double.compareTo() Method in Java with Examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。