Java Java lang.Long.numberOfLeadingZeros()用法及代码示例

java.lang.Long.numberOfLeadingZeros()是Java中的内置函数，它返回最高顺序设置位左侧的前导零位的数量。简单来说，它返回(64位置)，其中位置是指从右起的最高顺序设置位。如果该数字不包含任何设置位(换句话说，如果该数字为零)，则返回64。

用法:

public static long numberOfLeadingZeros(long num)
Parameters:
num - the number passed 
Returns:
the number of leading zeros before the highest-order set bit

例子：

Input:8
Output:60
Explanation:Binary representation of 8 is 1000 
No of leading zeros to the left of the highest-order set
bit is 60. 

Input:25
Output:59

以下示例程序旨在说明java.lang.Long.numberOfLeadingZeros()函数：

程序1:

// Java program that demonstrates the 
// Long.numberOfLeadingZeros() function 
  
// include lang package 
import java.lang.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        long l = 8; 
  
        // returns the number of zero bits before the highest-order 
        // set bit 
        System.out.println("Number of leading zeros = "
                           + Long.numberOfLeadingZeros(l)); 
  
        // second example 
        l = 25; 
        System.out.println("Number of leading zeros = "
                           + Long.numberOfLeadingZeros(l)); 
    } 
}

输出：

Number of leading zeros = 60
Number of leading zeros = 59

注意：如果是负数，则每个数字都将有0个前导零。

程序2:下面的程序演示了传递负数时函数的使用。

// Java program that demonstrates the 
// Long.numberOfLeadingZeros() function 
// negative number 
// include lang package 
import java.lang.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        long l = -12; 
  
        // returns the number of zero bits before the highest-order 
        // set bit 
        System.out.println("Number of leading zeros = "
                           + Long.numberOfLeadingZeros(l)); 
  
        l = -100; 
        System.out.println("Number of leading zeros = "
                           + Long.numberOfLeadingZeros(l)); 
    } 
}

输出：

Number of leading zeros = 0
Number of leading zeros = 0

程序3:当将十进制字符串值作为参数传递时，它将返回错误消息。

// Java program that demonstrates the 
// Long.numberOfLeadingZeros() function 
// decimal number 
// include lang package 
import java.lang.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // returns the number of zero bits before the highest-order 
        // set bit 
        System.out.println("Number of leading zeros = "
                           + Long.numberOfLeadingZeros(10.45)); 
    } 
}

输出：

prog.java:16:error:incompatible types:possible lossy conversion from double to long
                           + Long.numberOfLeadingZeros(10.45));

程序4:在参数中传递字符串值时。

// Java program that demonstrates the 
// Long.numberOfLeadingZeros() function 
// string number 
// include lang package 
import java.lang.*; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // returns the number of zero bits before the highest-order 
        // set bit 
        System.out.println("Number of leading zeros = "
                           + Long.numberOfLeadingZeros("10")); 
    } 
}

输出：

prog.java:16:error:incompatible types:String cannot be converted to long
                           + Long.numberOfLeadingZeros("10"));

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 lang.Long.numberOfLeadingZeros() 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。