为什么 gettype() 说它是 double 而 var_dump() 说它是 float？

Question

为什么 gettype() 说它是 double 而 var_dump() 说它是 float？

$number = 1234567890123456789;
echo "Number: {$number} is a ". gettype($number) . "\n";
var_dump($number);

回复：

数字：1.23456789012E+18 是一个双精度
浮动（1.23456789012E+18）

Answer 1

它们是同一件事 http://php.net/manual/en/language .types.float.php

Answer 2

直接来自 PHP.net (gettype())：

返回字符串的可能值为：

...
“double”（由于历史原因，在浮点情况下返回“double”，而不是简单的“float”） ...

Answer 3

<br>
<?php 
        /*begins with a function that runs a Console msg for PHP */
function console_sn($txt){
$temp = "";
$temp .= "<script>";
$temp .= "console.info('frm_PHP: '+'";
$temp .= $txt;
$temp .= "');";
$temp .= "</script>";
echo $temp;
}
echo("<br><hr><br>");
//end of PHP console function

//Main primary code for this Example begins below

//run these examples below in your test PHP file and see the results in your JS console window

//e.g.#1
$code1 = "1212";
console_sn(gettype(floatval($code1)));

//e.g.#2
$code2 = "1212sn";
console_sn(gettype(floatval($code2)));

//e.g.#3
$code3 = "1212";
console_sn(gettype((trim($code3))*1));

//e.g.#4
$code4 = "1212sn";
console_sn(gettype((trim($code4))*1));

?>