php false null 0 array string

php灵活的类型，我们比较一下他们的关系

echo false == array(); ✔️echo false == null; ✔️echo false == 0; ✔️echo false == 'asdf'; 错echo false == '0asdf'; 错echo 0 == '0asdf'; ✔️echo 0 == array(); ✔️echo null == array(); ✔️echo 'sdf' == array(); 错echo '0sdf' == array(); 错echo '0sd' == null; 错echo '' == null;  ✔️echo 0 == null; ✔️echo false == null; ✔️echo null == array(); ✔️

比较特殊的是’0sfd’ == 0 字符串是数字开头和数字比较的时候会是开头的数字