php执行这段代码会经过如下4个步骤(确切的来说，应该是php的语言引擎zend)

1.scanning(lexing) ,将php代码转换为语言片段(tokens)

2.parsing, 将tokens转换成简单而有意义的表达式

3.compi八年级数学试题lation, 将表达式编译成opocdes

4.execution, 顺次执行opcodes，每次一条，从而实现php脚本的功能。

token_get_all()

将一段php代码 scanning成tokens；

var_dump(token_get_all(‘<?php echo “hello world”; ?>’));

array(

[0] => array(

[0] => 376

[1] => <?php

[2] => 1 )

[1] => array(

horrible[0] => 319

[1] => echo

[2] => 1 )

[2] => array(

[0] => 379

[1] =>

[2] => 1 )

[3] => arrafindsy(一箪食读音

[0] => 318

[1] => “hello world”

[2] => 1 )

[4] => ;

[5] => array(

[0蜀道之难] => 379

[1] =>

[2] => 1 )

[6] => array(

[0] => 378

[1] => ?>

[2] => 1 )

)