gmp_cmp

(PHP 4 >= 4.0.4, PHP 5)

gmp_cmpCompare numbers

Description

int gmp_cmp ( resource $a , resource $b )

Compares two numbers.

Parameters

a

It can be either a GMP number resource, or a numeric string given that it is possible to convert the latter to a number.

b

It can be either a GMP number resource, or a numeric string given that it is possible to convert the latter to a number.

Return Values

Returns a positive value if a > b, zero if a = b and a negative value if a < b.

Examples

Example #1 gmp_cmp() example

<?php
$cmp1 
gmp_cmp("1234""1000"); // greater than
$cmp2 gmp_cmp("1000""1234"); // less than
$cmp3 gmp_cmp("1234""1234"); // equal to

echo "$cmp1 $cmp2 $cmp3\n";
?>

The above example will output:

1 -1 0

Коментарии

I've encountered a memory leak in gmp_cmp if a literal string is used as the second value inside of loops. A workaround is to initialize first, then use the variable. I wasn't able to generate a minimum code sample, it's something more complicated, but I was able to fix it as follows:

<?php

$x 
gmp_init(strval(mt_rand()));

// Depending on surrounding code, may have leaks
while (true)
{
    if (!
gmp_cmp($x'1'))
        print 
'one'."\n";
}

// Usually doesn't have leaks
$one gmp_init('1');

while (
true)
{
    if (!
gmp_cmp($x$one))
        print 
'one'."\n";
}

?>
2010-07-28 16:43:54
http://php5.kiev.ua/manual/ru/function.gmp-cmp.html

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