表单 post过来的是字符串类型么？-PHP Tutorial-php.cn

表单 post过来的是字符串类型么？

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Release： 2016-06-23 14:05:48

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1.表单post过来的是字符串类型么？
2.如果是字符串类型，那么下面这段怎么解释，为何不经过类型转换就可以直接相加？Python可不是这样的哦

<html><?php// create short variable names $tireqty = $_POST['tireqty']; $oilqty = $_POST['oilqty']; $sparkqty = $_POST['sparkqty']; // create constant names define ('TIREPRICE',100); define ('OILPRICE',10); define ('SPARKPRICE',4);?> <head>  <title>Bob's Auto Parts - Order Result</title> </head> <body>  <h1>Bob's Auto Parts</h1>  <h2>Order Results</h2>  <?php    //echo '<p>Order processed.</p>';   echo '<p>Order processed at '.date('H:i , jS F Y').'</p>';   // overcome not integer number   if (is_string($tireqty) == True or is_string($oilqty) == True or is_string($sparkqty) == True)   {   		echo "one of your input is type string.<br/>";   		echo '<p>Your order is as follow: </p>';   		echo $tireqty. ' tires. <br/>';   		echo $oilqty.  ' bottles of oil<br/>';   		echo $sparkqty. ' spark plugs<br/>';       // calc total items ordered    $totalqty = 0;    $totalqty = $tireqty + $oilqty + $sparkqty;        if ($totalqty == 0)    {     	echo 'You did not order anything on the previous page!<br/>';    }    else     {    	echo "Items ordered: $totalqty <br/>";    	    	// calc total amount    	$toatlamount = 0;    	$toatlamount = $tireqty * TIREPRICE + $oilqty * OILPRICE + $sparkqty * SPARKPRICE;    	echo 'Subtotal: $'.number_format($toatlamount,2).'<br/>';    	    	// calc total tax	    	$taxrate = 0.10;    	$totaltaxrate = 0;    	$totaltaxrate = $toatlamount * 0.10;    	echo 'Total tax: $'.number_format($totaltaxrate,2).'<br/>';    }   }  ?> </body></html>

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运行结果:

Bob's Auto PartsOrder ResultsOrder processed at 17:33 , 15th April 2013one of your input is type string.Your order is as follow: 1 tires. 2 bottles of oil3 spark plugsItems ordered: 6 Subtotal: $132.00Total tax: $13.20

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回复讨论(解决方案)

python的字符串连接符和算数相加都是+号，如果你 '1'+'2'， python没法明白你的意思，到底相加还是相连？它可不能自作主张，只好严格按类型运算。
但PHP的字符串连接符是 . 号，如果你用 '1'+'2'; 它当然明白你是想相加，而不是相连。因此结果自然是3，而不是'12'。甚至你用 '1'+'ssss' 也会得到数字1

1. 是字符串类型。
2. 有很多语言有自动Cast的功能的。

呵呵呵刚开始接触弱类型语言的时候都有这类想发，习惯就好了...

python是弱类型，是不需要声明字段属性的，python虽然是弱类型，但是不会将字段类型默认识别。

传递是什么类型就还是什么类型