в 10:37, 26 мая 2010

2010-05-26T10:37:31Z

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2010-05-26T07:06:06Z

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==Finding a random line of a file==



<source lang="html4strict">

<?php
function randomint($max = 1) {
$m = 1000000;
return ((mt_rand(1,$m * $max)-1)/$m);
}
?>
$line_number = 0;
$fh = fopen("data.txt","r") or die($php_errormsg);
while (! feof($fh)) {
if ($s = fgets($fh)) {
$line_number++;
if (randomint($line_number) < 1) {
$line = $s;
}
}
}
fclose($fh) or die($php_errormsg);
?>

</source>

==Generate Password()==



<source lang="html4strict">

<?php
function GeneratePassword($min = 5, $max = 8) {
$ValidChars = "abcdefghijklmnopqrstuvwxyz123456789";
$max_char = strlen($ValidChars) - 1;
$length = mt_rand($min, $max);
$password = "";
for ($i = 0; $i < $length; $i++) {
$password .= $ValidChars[mt_rand(0, $max_char)];
}
return $password;
}
echo "New Password = " . GeneratePassword() . "\n";
echo "New Password = " . GeneratePassword(4, 10) . "\n";
?>

</source>

==Generate random floating-point values from 0 to 10 with two decimals==



<source lang="html4strict">

<?php
function frand($min, $max, $decimals = 0) {
$scale = pow(10, $decimals);
return mt_rand($min * $scale, $max * $scale) / $scale;
}
echo "frand(0, 10, 2) = " . frand(0, 10, 2) . "\n";
?>

</source>

==Generate random numbers==



<source lang="html4strict">

<?php
function frand($min, $max, $precision = 1) {
$scale = 1/$precision;
return mt_rand($min * $scale, $max * $scale) / $scale;
}
echo "frand(0, 10, 0.25) = " . frand(0, 10, 0.25) . "\n";
?>

</source>

==Get a random value from 5 to 25.==



<source lang="html4strict">

<?php
echo "rand(5, 25) = " . rand(5, 25) . "\n";
echo "mt_rand(5, 25) = " . mt_rand(5, 25) . "\n";
?>

</source>

==Get random values from �10 to 10.==



<source lang="html4strict">

<?php
echo "rand(-10, 10) = " . rand(-10, 10) . "\n";
echo "mt_rand(-10, 10) = " . mt_rand(-10, 10) . "\n";
?>

</source>

==int mt_rand ( [int min, int max] ) returns random numbers, similar to the rand( ).==



<source lang="html4strict">

It uses the Mersenne Twister algorithm to generate "better" random numbers (i.e., more random), and is often preferred.
<?
$mtrand = mt_rand( );
$mtrandrange = mt_rand(1,100);
?>

</source>

==Random floating-point values from 0 to 10 with two decimals==



<source lang="html4strict">

<?php
function frand($min, $max, $decimals = 0) {
$scale = pow(10, $decimals);
return mt_rand($min * $scale, $max * $scale) / $scale;
}
echo "frand(0, 10, 2) = " . frand(0, 10, 2) . "\n";
?>

</source>

==Random numbe with precision==



<source lang="html4strict">

<?php
function frand($min, $max, $precision = 1) {
$scale = 1/$precision;
return mt_rand($min * $scale, $max * $scale) / $scale;
}
echo "frand(0, 10, 0.25) = " . frand(0, 10, 0.25) . "\n";
?>

</source>

==Random values are not restricted to positive integers. The following example shows how to get random values from -10 to 10.==



<source lang="html4strict">

<?php
echo "rand(-10, 10) = " . rand(-10, 10) . "\n";
echo "mt_rand(-10, 10) = " . mt_rand(-10, 10) . "\n";
?>

</source>

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в 10:37, 26 мая 2010

Admin: 1 версия