php 0到1.0之间的随机浮点数php
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Random float number between 0 and 1.0 php
提问by Matthew Underwood
Possible Duplicate:
Random Float in php
可能的重复：
php 中的随机浮点数
Is it possible to create a random float number between 0 and 1.0 e.g 0.4, 0.8 etc. I used rand but it only accepts integers.
是否可以创建一个介于 0 和 1.0 之间的随机浮点数，例如 0.4、0.8 等。我使用了 rand 但它只接受整数。
回答by Francois Bourgeois
mt_rand() / mt_getrandmax();
Avoid the rand()function, since it usually depends on the platform's C rand()implementation, generally creating numbers with a very simple pattern. See this comment on php.net
避免使用该rand()函数，因为它通常取决于平台的 Crand()实现，通常使用非常简单的模式创建数字。在 php.net 上查看此评论
回答by h2ooooooo
What about simply dividing by 10?
简单地除以 10 怎么样？
$randomFloat = rand(0, 10) / 10;
var_dump($randomFloat);
//eg. float(0.7)
回答by Paolo
$v = mt_rand() / mt_getrandmax();
will do that.
会这样做。
In case you want only one decimal place (as in the examples from the question) just round()the value you get...
如果您只想要一个小数位（如问题中的示例），round()那么您只需要获得的值...
$v = round( $v, 1 );
...or calculate a number between 0 and 10 and divide by 10:
...或计算 0 到 10 之间的数字并除以 10：
$v = mt_rand( 0, 10 ) / 10;
回答by Nemo Caligo
According to the PHP documentation, if you're using PHP 7 you can generate a cryptographically secure pseudorandom integer using random_int
根据 PHP 文档，如果您使用的是 PHP 7，则可以使用random_int生成加密安全的伪随机整数
With that said, here's a function that utilizes this to generate a random float between two numbers:
话虽如此，这是一个利用它在两个数字之间生成随机浮点数的函数：
function random_float($min, $max) {
return random_int($min, $max - 1) + (random_int(0, PHP_INT_MAX - 1) / PHP_INT_MAX );
}
Although random_int() is more secure than mt_rand(), keep in mind that it's also slower.
尽管 random_int() 比 mt_rand() 更安全，但请记住，它也更慢。
A previous version of this answer suggested you use PHP rand(), and had a horrible implementation. I wanted to change my answer without repeating what others had already stated, and now here we are.
此答案的先前版本建议您使用 PHP rand()，并且实现方式很糟糕。我想在不重复其他人已经说过的内容的情况下更改我的答案，现在我们来了。
回答by Dracony
how about this simple solution:
这个简单的解决方案怎么样：
abs(1-mt_rand()/mt_rand())
or
或者
/**
* Generate Float Random Number
*
* @param float $Min Minimal value
* @param float $Max Maximal value
* @param int $round The optional number of decimal digits to round to. default 0 means not round
* @return float Random float value
*/
function float_rand($Min, $Max, $round=0){
//validate input
if ($min>$Max) { $min=$Max; $max=$Min; }
else { $min=$Min; $max=$Max; }
$randomfloat = $min + mt_rand() / mt_getrandmax() * ($max - $min);
if($round>0)
$randomfloat = round($randomfloat,$round);
return $randomfloat;
}
回答by Nandu
Try this
尝试这个
// Generates and prints 100 random number between 0.0 and 1.0
$max = 1.0;
$min = 0.0;
for ($i = 0; $i < 100; ++$i)
{
print ("<br>");
$range = $max - $min;
$num = $min + $range * (mt_rand() / mt_getrandmax());
$num = round($num, 2);
print ((float) $num);
}
回答by Oliver Charlesworth
Cast to float*and divide by getrandmax().
转换为浮动*并除以getrandmax()。
* It seems that the cast is unnecessary in PHP's arbitrary type-juggling rules. It would be in other languages, though.* 在 PHP 的任意类型杂耍规则中，似乎不需要强制转换。不过，它会是其他语言。
