gmp_testbit will be very useful for my (over 64-bit) bitmask checking.
In the meantime, I think these are the best replacements.
Mostly full:
<?php
(gmp_scan1($a, $index) == $index)
?>
Mostly empty:
<?php
(gmp_scan0($a, $index) != $index)
?>
Still worst-case O(N), though.
gmp_testbit
(PHP 5 >= 5.3.0, PHP 7, PHP 8)
gmp_testbit — Tests if a bit is set
返回值
Returns true if the bit is set in num,
otherwise false.
错误／异常
An E_WARNING level error is issued when
index is less than zero, and false
is returned.
示例
示例 #1 gmp_testbit() example
<?php
$n = gmp_init("1000000");
var_dump(gmp_testbit($n, 1));
gmp_setbit($n, 1);
var_dump(gmp_testbit($n, 1));
?>以上示例会输出：
bool(false) bool(true)
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User Contributed Notes 1 note
bluej100@gmail ¶
17 years ago
