为什么 true 输出 1,可是 false 却什么也不输出呢?
<br /><?php<br /><br />$a=true;<br /><br />echo "下面输出 true <br>";<br /><br />echo $a;<br /><br />echo '<br>';<br /><br />$a=false;<br /><br />echo "下面输出 false <br>";<br /><br />echo $a;<br />?><br />
如果真转化为1输出,那么,假就应该转化为0输出呀。
------解决方案--------------------
按它定的规则来,这就是编程
------解决方案--------------------
$a = false;
var_dump($a);
输出:
bool(false)
建议使用var_dump()进行调试
------解决方案--------------------
语言的作者就这么写的,等哪天你写个语言让false输出0,true什么也不输出,后来有人问为什么false输出0,而true什么都不输出呢
------解决方案--------------------
php 的布尔值true和false; //echo true;为1 echo false 不会有任何输出内容
php和c一样,0表示false;非0表示true;
<br />$a=1;<br /><br />echo "下面输出 true <br>";<br /><br />echo $a;<br /><br />echo '<br>';<br /><br />$a=0;<br /><br />echo "下面输出 false <br>";<br /><br />echo $a;<br />
------解决方案--------------------
对于数字类型来说,false 确实 是 0, 而对string来说,false是 空,虽然数字的0也等于字符串的空,但是不能说 bool 转换 string 以后就是 0;
var_dump((int)false);<br />var_dump((string)false);
------解决方案--------------------
..........

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