PHP GMP gmp_clrbit() Function

As of my last update in September 2021, PHP’s GMP (GNU Multiple Precision) extension includes the gmp_clrbit() function. The gmp_clrbit() function is used to clear (set to 0) a specific bit in a GMP number.

Here’s the syntax of the gmp_clrbit() function:

GMP gmp_clrbit ( GMP $num , int $index )

Parameters:

• $num: The GMP number in which you want to clear a bit.
• $index: The index of the bit to clear. Indexing starts from 0 for the least significant bit (LSB).

Return value:

• The gmp_clrbit() function returns a new GMP number with the specified bit cleared.

Example:

$number = gmp_init('13'); // Binary: 1101

$clearedBitNumber = gmp_clrbit($number, 1); // Clear the bit at index 1 (second bit from the right)

echo "The GMP number with the bit at index 1 cleared: " . gmp_strval($clearedBitNumber); // Output: 9 (Binary: 1001)

In this example, the gmp_clrbit() function is used to clear the bit at index 1 (the second bit from the right) in the GMP number 13. The resulting GMP number is 9, which represents the binary value 1001 after clearing the second bit.

The gmp_clrbit() function can be useful for manipulating individual bits in a GMP number. It allows you to efficiently modify specific bits in large integers without affecting other bits.

Please note that the GMP extension needs to be enabled in your PHP configuration to use this function. Additionally, the availability of functions may change in newer PHP versions, so always refer to the PHP manual for the specific version you are using.