Java long compareTo()用法及代码示例

java.lang.Long.compareTo()是java中的内置方法，该方法以数字方式比较两个Long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)

Parameter:
obj - The object which is to be compared to.

返回值：该函数返回三个值：

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

程序1:下面的程序演示了函数的工作。

// Java program to demonstrate 
// of java.lang.Long.compareTo() method 
import java.lang.Math; 
  
class Gfg1 { 
  
    // driver code 
    public static void main(String args[]) 
    { 
  
        // when two objects are different 
        Long obj1 = new Long(124); 
        Long obj2 = new Long(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

程序2:下面的程序演示了不传递任何参数时函数的工作方式

// Java program to demonstrate 
// of java.lang.Long.compareTo() method 
import java.lang.Math; 
  
class Gfg1 { 
  
    // driver code 
    public static void main(String args[]) 
    { 
        // when no argument is passed 
        Long obj1 = new Long(124); 
        Long obj2 = new Long(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 Long cannot be applied to given types;
      int compareValue = obj1.compareTo(); 
                             ^
  required:Long
  found:no arguments
  reason:actual and formal argument lists differ in length
1 error

程序3:下面的程序演示了在参数中传递对象以外的任何东西时函数的工作方式

// Java program to demonstrate 
// of java.lang.Long.compareTo() method 
import java.lang.Math; 
  
class Gfg1 { 
  
    // driver code 
    public static void main(String args[]) 
    { 
  
        // when anything other than object 
        // argument is passed 
        Long obj1 = new Long(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:14:error:incompatible types:String cannot be converted to Long
      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gopaldave大神的英文原创作品 Java long compareTo() 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。