它们主要用于位操作(惊喜)。下面是在PHP代码库中找到的一些实际示例。

字符编码:

if (s <= 0 && (c & ~MBFL_WCSPLANE_MASK) == MBFL_WCSPLANE_KOI8R) {

数据结构:

ar_flags = other->ar_flags & ~SPL_ARRAY_INT_MASK;

数据库驱动程序:

dbh->transaction_flags &= ~(PDO_TRANS_ACCESS_MODE^PDO_TRANS_READONLY);

编译器实现:

opline->extended_value = (opline->extended_value & ~ZEND_FETCH_CLASS_MASK) | ZEND_FETCH_CLASS_INTERFACE;

按位&用于屏蔽/提取字节的某一部分。

1字节变量

 01110010
&00001111 Bitmask of 0x0F to find out the lower nibble
 --------
 00000010

特别是移位运算符(<< >>)经常用于计算。

我使用它们作为选项处理程序，例如在访问控制列表中描述特定的资源。

看看这篇文章http://planetozh.com/blog/2006/05/php-bitwise-operators-example-of-use/

还有一个链接: http://blog.code-head.com/how-to-write-a-permission-system-using-bits-and-bitwise-operations-in-php

河内塔线性解采用位运算来解决问题。

public static void linear(char start, char temp, char end, int discs)
{
    int from,to;
    for (int i = 1; i < (1 << discs); i++) {
        from = (i & i-1) % 3;
        to = ((i | i-1) + 1) % 3;
        System.out.println(from+" => "+to);
    }
}

这个解决方案的解释可以在这里找到

Bit fields (flags) They're the most efficient way of representing something whose state is defined by several "yes or no" properties. ACLs are a good example; if you have let's say 4 discrete permissions (read, write, execute, change policy), it's better to store this in 1 byte rather than waste 4. These can be mapped to enumeration types in many languages for added convenience. Communication over ports/sockets Always involves checksums, parity, stop bits, flow control algorithms, and so on, which usually depend on the logic values of individual bytes as opposed to numeric values, since the medium may only be capable of transmitting one bit at a time. Compression, Encryption Both of these are heavily dependent on bitwise algorithms. Look at the deflate algorithm for an example - everything is in bits, not bytes. Finite State Machines I'm speaking primarily of the kind embedded in some piece of hardware, although they can be found in software too. These are combinatorial in nature - they might literally be getting "compiled" down to a bunch of logic gates, so they have to be expressed as AND, OR, NOT, etc. Graphics There's hardly enough space here to get into every area where these operators are used in graphics programming. XOR (or ^) is particularly interesting here because applying the same input a second time will undo the first. Older GUIs used to rely on this for selection highlighting and other overlays, in order to eliminate the need for costly redraws. They're still useful in slow graphics protocols (i.e. remote desktop).

这些只是我最先想到的几个例子——这不是一个详尽的清单。

我见过它们在基于角色的访问控制系统中使用。