Php设置变量属性默认值在php 7.1中不起作用

Question

I have a variable property set default value array, it works in my php 5.6 localhost but not working when i upload to server with php 7.1 , can anyone tell me why?

class foo {
    var $bar = array();

    function baz($data) {
        $this->bar['data'] = $data; <---- works in php 5.6, not working in php 7.1
    }
}

in php 7.1, I have to update variable property in construct

function __construct(){
    $this->bar = array();
}

Answer 1

The code you provided produces very same result from PHP version 7.1.25 to 7.3.2 (check on 3v4l.org):

object(foo)#1 (1) {
  ["bar"]=>
  array(1) {
    ["data"]=>
    int(22)
  }
}

Even it works, I would suggest ALWAYS initializing class properties in __construct as you discovered too:

function __construct(){
    $this->bar = array();
}

more importantly, prefer using one of public/protected or private visibility modifiers, rather than var which turns into a public under the hood.