PHP | gmp_sign() Function

The gmp_sign() is an in-built function in PHP which checks the sign of a given GMP number (GNU Multiple Precision: For large numbers). Syntax:

gmp_sign($num)

Parameters: This function accepts one GMP number $num as mandatory parameter shown in the above syntax. This parameter can be a GMP object in PHP version 5.6 and later, or we are also allowed to pass a numeric string provided that it is possible to convert that string to a number. Return Value: The function checks the sign of the given number $num and returns three values depending on the number as described below:

• Returns 1 - $num is positive
• Returns -1 - $num is negative
• Returns 0 - $num is zero

Examples:

 Input : $num=9 Output : 1 Input : $num=-8 Output : -1 Input : $num=0 Output : 0 

Below programs illustrate the gmp_sign() function: Program 1: The program below demonstrates the working of gmp_sign() function when GMP number is passed as an argument. php

<?php // PHP program to check the sign  // of a number  // GMP arguments  // negative  $num1 = gmp_init("-101", 2); // positive $num2 = gmp_init("1010", 2); // zero $num3 = gmp_init("0", 2); // prints -1 as negative echo gmp_sign($num1)."\n"; // prints +1 as negative echo gmp_sign($num2)."\n"; // prints 0 as 0 echo gmp_sign($num3)."\n"; ?> 

Output:

 -1 1 0 

Program 2: The program below demonstrates the working of gmp_sign() when numeric string is passed as an argument. php

<?php // PHP program to check the sign  // of a number  // numeric arguments  // negative  $num1 = -9; // positive $num2 = 8; // zero $num3 = 0; // prints -1 as negative echo gmp_sign($num1)."\n"; // prints +1 as negative echo gmp_sign($num2)."\n"; // prints 0 as 0 echo gmp_sign($num3)."\n"; ?> 

Output:

-1 1 0

Reference: http://php.net/manual/en/function.gmp-sign.php