The origin of the problem: Will if(true==2) in PHP return true or false?
The result is true. Following this question, I will also test other data types of PHP.
Conclusion:
When converted to bool type, several types of data will become false:
1.Integer type 0
2. Empty string
3. Empty array
4.NULL
Additions are welcome...
Test code:
<?php
function p($title,$mybool){
echo "<pre class="brush:php;toolbar:false">".$title;
echo var_dump($mybool)."";
}
class foo {
function do_foo() {
echo "你好！";
}
}
echo"PHP中的其他类型转化为Bool类型"; //零 $n0=boolval(0); p("零：",$n0); //正整数 $n=boolval(2); p("正整数：",$n); //负整数 $nx=boolval(-2); p("负整数：",$nx); //字符空格 $ss=boolval(" "); p("字符空格：",$ss); //空字符串 $sn=boolval(""); p("空字符串：",$sn); //字符串 $s=boolval("chinacion"); p("字符串：",$s); //空数组 $an=boolval(array()); p("空数组：",$an); //数组 $a=boolval(array(0=>1)); p("数组：",$a); //null类型 $nu = boolval(NULL); p("NULL：",$nu); //object $bar = new foo; $bar; $obj = boolval($bar); p("Object：",$obj);
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