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  • gmp_scan1()

    (PHP 4 >= 4.0.4, PHP 5, PHP 7)

    Scan for 1

    说明

    gmp_scan1(GMP$a,int $start): int

    Scans$a, starting with bit$start, towards more significant bits, until the first set bit is found.

    参数

    $a

    The number to scan.

    可以是一个 GMP数据resouce,或一个可以转换为数值的字符串。

    $start

    The starting bit.

    返回值

    Returns the index of the found bit, as an integer. If no set bit is found,-1 is returned.

    范例

    gmp_scan1() example

    <?php
    // "1" bit is found at position 3. index starts at 0
    $s1 = gmp_init("01000", 2);
    echo gmp_scan1($s1, 0) . "\n";
    // "1" bit is found at position 9. index starts at 5
    $s2 = gmp_init("01000001111", 2);
    echo gmp_scan1($s2, 5) . "\n";
    ?>
    

    以上例程会输出:

    3
    9
    

    上篇:gmp_scan0()

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