Java Java lang.Long.numberOfLeadingZeros()用法及代碼示例

java.lang.Long.numberOfLeadingZeros()是Java中的內置函數，它返回最高順序設置位左側的前導零位的數量。簡單來說，它返回(64位置)，其中位置是指從右起的最高順序設置位。如果該數字不包含任何設置位(換句話說，如果該數字為零)，則返回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

以下示例程序旨在說明java.lang.Long.numberOfLeadingZeros()函數：

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)); 
    } 
}

輸出：

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

注意：如果是負數，則每個數字都將有0個前導零。

程序2:下麵的程序演示了傳遞負數時函數的使用。

// 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)); 
    } 
}

輸出：

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

程序3:當將十進製字符串值作為參數傳遞時，它將返回錯誤消息。

// 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)); 
    } 
}

輸出：

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

程序4:在參數中傳遞字符串值時。

// 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")); 
    } 
}

輸出：

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

相關用法

注：本文由純淨天空篩選整理自gopaldave大神的英文原創作品 Java lang.Long.numberOfLeadingZeros() method in Java with Examples。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。