php字符串转换问题
$num="";
for($i=0;$i $num .= dechex(rand(0,15));
}
以上代码，dechex(rand(0,15))，应该得到的是数字？但是却$num .
这怎么理解。。
------解决方案--------------------
dechex的返回值是一个字符串呀
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