Important
1. Note that a case-insensitive
<?php
$flag=true;
$run=FALSE;//注意不区分大小写
$version="1.2.3";
//使用字符控制逻辑
if ($version=="1.2.3") {
echo "hello";
}
if ($flag==TRUE) {
echo "Yes";
}else {
echo "NO";
}
if ($run) {
echo "开始跑了";
}
else {
echo "压根儿没动";
}
?>Learning Important
Note: 0,0.0, "", "0 ", "0.0", NULL, [empty array types are converted into the false} bool
and JavaScript somewhat similar, then these values are false logic operations involved in
<?php
//0，0.0，""，"0"，"0.0"，NULL 空数组
var_dump((bool)0);//false
var_dump((bool)9);//true
var_dump((bool)-5);//true
var_dump((bool)3.1415);//true
var_dump((bool)0.0);//false
var_dump((bool)"");//false
var_dump((bool)"0");//false
var_dump((bool)" ");//true
var_dump((bool)"flag");//true
var_dump((bool)"false");//true
var_dump((bool)null);//false
var_dump((bool)array(12));//true
var_dump((bool)array());//false
?>
