php - 什么是 php 中的 System.out 或 systemout？

Question

我正在探索 php，我发现了system.out和systemout。php 说它们是字符串，但它们的行为不像字符串。这里有些例子。

    system.out.print('test');
    //output
    test

    system.out.var_dump('system.out');
    // output
    string(9) "systemout"


    systemout.var_dump('test');
    // output 

string(4) "test"

这是语言错误吗？

Answer 1

让我在代码中这样说：

in.fact.you.can.concat.many.undefined.constants.with.any.func.print('.');

如果你启用了错误报告，php 会通知你许多未定义的常量，它们将被视为字符串，因此将被视为：

'in'.'fact'.'you'.'can'.'concat'.'many'.'undefined'.'constants'.'with'.'any'.'func'.print('.');

产生所需输出的唯一方法是函数调用。此函数的返回值连接到未定义常量的字符串，并且什么也不做。

Answer 2

//i can tell what you are trying to do.is to dumb some vars to console.
//System.out.printLn does not exist in php

//there are other tools like firephp but this is the simplest method to log vars to console
//use the following function instead in php
function phpconsole($label='var',$x){
?>
 <script type="text/javascript">
   console.log('<?php echo ($label)?>');
   console.log('<?php echo json_encode($x)?>');
  </script>
 <?php
}
//use it like this
$salary = 500;
phpconsole('salary:',$salary);

$arr = array('aaa','bbb','ccc');
phpconsole('arr:',$arr);//it will accept any datatype and dumb it to console