gmp_init(3) [php man page]

GMP_INIT(3)								 1							       GMP_INIT(3)

gmp_init - Create GMP number

SYNOPSIS

       GMP gmp_init (mixed  $number, [int  $base])

DESCRIPTION

	Creates a GMP number from an integer or string.

PARAMETERS

	      o $number
		- An integer or a string. The string representation can be decimal, hexadecimal or octal.

	      o $base
		-  The base.  The base may vary from 2 to 36. If base is 0 (default value), the actual base is determined from the leading charac-
		ters: if the first two characters are 0x or 0X, hexadecimal is assumed, otherwise if the first character is "0", octal is assumed,
		otherwise decimal is assumed.

RETURN VALUES

	A GMP number resource in PHP 5.5 and earlier, or a GMP object in PHP 5.6 and later.

CHANGELOG

       +--------+---------------------------------------------------+
       |Version |						    |
       |	|						    |
       |	|		     Description		    |
       |	|						    |
       +--------+---------------------------------------------------+
       | 5.3.2	|						    |
       |	|						    |
       |	|  The	$base was extended from 2 to 36, to 2 to 62 |
       |	| and -2 to -36.				    |
       |	|						    |
       +--------+---------------------------------------------------+
NOTES

       Note

	       To use the extended base introduced in PHP 5.3.2, then PHP must be compiled against GMP 4.2.0 or greater.

EXAMPLES

       Example #1

	      Creating GMP number

	      <?php
	      $a = gmp_init(123456);
	      $b = gmp_init("0xFFFFDEBACDFEDF7200");
	      ?>

NOTES

       Note

	       It is not necessary to call this function if you want to use integer or string in place	of  GMP  number  in  GMP  functions,  like
	      gmp_add(3). Function arguments are automatically converted to GMP numbers, if such conversion is possible and needed, using the same
	      rules as gmp_init(3).

PHP Documentation Group 													       GMP_INIT(3)

GMP_SETBIT(3)								 1							     GMP_SETBIT(3)

gmp_setbit - Set bit

SYNOPSIS

       void gmp_setbit (GMP  &$a, int  $index, [bool  $bit_on = true])

DESCRIPTION

	Sets bit $index in $a.

PARAMETERS

	      o $a
		- The value to modify. Either a GMP number resource in PHP 5.5 and earlier, a GMP object in PHP 5.6 and later, or a numeric string
		provided that it is possible to convert the latter to a number.

	      o $index
		- The index of the bit to set. Index 0 represents the least significant bit.

	      o $bit_on
		- True to set the bit (set it to 1/on); false to clear the bit (set it to 0/off).

RETURN VALUES

	A GMP number resource in PHP 5.5 and earlier, or a GMP object in PHP 5.6 and later.

EXAMPLES

       Example #1

	      gmp_setbit(3) example - 0 index

	      <?php
	      $a = gmp_init("2"); //
	      echo gmp_strval($a), ' -> 0b', gmp_strval($a, 2), "
";
	      gmp_setbit($a, 0); // 0b10 now becomes 0b11
	      echo gmp_strval($a), ' -> 0b', gmp_strval($a, 2), "
";
	      ?>

	      The above example will output:

	      2 -> 0b10
	      3 -> 0b11

       Example #2

	      gmp_setbit(3) example - 1 index

	      <?php
	      $a = gmp_init("0xfd");
	      echo gmp_strval($a), ' -> 0b', gmp_strval($a, 2), "
";
	      gmp_setbit($a, 1); // index starts at 0
	      echo gmp_strval($a), ' -> 0b', gmp_strval($a, 2), "
";
	      ?>

	      The above example will output:

	      253 -> 0b11111101
	      255 -> 0b11111111

       Example #3

	      gmp_setbit(3) example - clearing a bit

	      <?php
	      $a = gmp_init("0xff");
	      echo gmp_strval($a), ' -> 0b', gmp_strval($a, 2), "
";
	      gmp_setbit($a, 0, false); // clear bit at index 0
	      echo gmp_strval($a), ' -> 0b', gmp_strval($a, 2), "
";
	      ?>

	      The above example will output:

	      255 -> 0b11111111
	      254 -> 0b11111110

NOTES

       Note

	       Unlike most of the other GMP functions, gmp_setbit(3) must be called with a GMP resource that already exists (using gmp_init(3) for
	      example). One will not be automatically created.

SEE ALSO

       gmp_clrbit(3), gmp_testbit(3).

PHP Documentation Group 													     GMP_SETBIT(3)