Java Integer highestOneBit()用法及代碼示例

java.lang的Integer.highestOneBit()方法返回一個整數值，該整數值最多具有單個one-bit，對於給定的int值，其位於highest-order(即最左側)one-bit的位置。如果指定的值在其補碼二進製表示形式中不包含one-bits，則其返回零(簡單地等於0)。

用法:

public static int highestOneBit(int a)

參數：該方法采用整數類型的一個參數a，該參數表示要返回其最高順序位或對其執行操作的值。

返回值：該方法可以返回兩種類型的值：

在指定值的highest-order one-bit的位置中返回一個1位整數值
如果指定值等於零，則返回零。

例子：

Input: 19
Output: Highest one bit of the given integer is = 16

Input: -9
Output: Highest one bit of the given integer is = -2147483648

Explanation:
Consider any integer a = 19
Binary Representation = 0001 0011
Highest bit(at 4) i.e.0001 0000
so result = 2^4=16

以下示例程序旨在說明Java.lang.Integer.highestOneBit()方法。
示例1:為正數。

// Java praogram to illustrate the 
// Java.lang.Integer.highestOneBit() Method 
import java.lang.*; 
  
public class HighestOneBit { 
  
    public static void main(String[] args) 
    { 
  
        int a = 29; 
        System.out.println("Number is = " + a); 
  
        // returns an int value with at most a single one-bit, in the position 
        // of the highest-order or the leftmost one-bit in the specified int value 
        System.out.print("Highest one bit of the given integer is = "); 
        System.out.println(Integer.highestOneBit(a)); 
        a = 44; 
        System.out.println("Number is = " + a); 
        System.out.print("Highest one bit of the given integer is = "); 
        System.out.println(Integer.highestOneBit(a)); 
    } 
}

輸出：

Number is = 29
Highest one bit of the given integer is = 16
Number is = 44
Highest one bit of the given integer is = 32

示例2:為負數。

// Java praogram to illustrate the 
// Java.lang.Integer.highestOneBit() Method 
import java.lang.*; 
  
public class HighestOneBit { 
  
    public static void main(String[] args) 
    { 
  
        int a = -9; 
        System.out.println("Number is = " + a); 
  
        // returns an int value with at most a single one-bit, in the position 
        // of the highest-order or the leftmost one-bit in the specified int value 
        System.out.print("Highest one bit of the given integer is = "); 
        System.out.println(Integer.highestOneBit(a)); 
    } 
}

輸出：

Number is = -9
Highest one bit of the given integer is = -2147483648

示例3:對於十進製值。
注意：由於類型不兼容而將十進製值作為參數傳遞時，它將返回錯誤消息。

// Java praogram to illustrate the 
// Java.lang.Integer.highestOneBit() Method 
import java.lang.*; 
  
public class HighestOneBit { 
  
    public static void main(String[] args) 
    { 
  
        int a = 84.22; 
        System.out.println("Number is = " + a); 
  
        // decimal value 84.22 is passed here 
        System.out.print("Highest one bit of the given integer is = "); 
        System.out.println(Integer.highestOneBit(a)); 
    } 
}

輸出：


prog.java:9: error: incompatible types: possible lossy conversion from double to int
    int a = 84.22;
            ^
1 error

示例4:對於字符串。
注意：由於類型不兼容而將字符串作為參數傳遞時，它將返回錯誤消息。

// Java praogram to illustrate the 
// Java.lang.Integer.highestOneBit() Method 
import java.lang.*; 
  
public class HighestOneBit { 
  
    public static void main(String[] args) 
    { 
  
        int a = "34"; 
        System.out.println("Number is = " + a); 
  
        // decimal value 84.22 is passed here 
        System.out.print("Highest one bit of the given integer is = "); 
        System.out.println(Integer.highestOneBit(a)); 
    } 
}

輸出：


prog.java:9: error: incompatible types: String cannot be converted to int
    int a = "34";
            ^
1 error

相關用法

注：本文由純淨天空篩選整理自ankita_chowrasia大神的英文原創作品 Integer highestOneBit() Method in Java。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。