数组前加echo '<pre>'; 出来格式化效果

test_yto.php 

<?php

$file = './write_str.xml';
$con = file_get_contents($file);
//XML标签配置
$xmlTag = array(
    'starttime',
    'endtime',
    'school'
);

$arr = array();
foreach($xmlTag as $x) {
    preg_match_all("/<".$x.">.*<\/".$x.">/", $con, $temp);
    $arr[] = $temp[0];
}
//去除XML标签并组装数据
$data = array();
foreach($arr as $key => $value) {
    foreach($value as $k => $v) {
        $a = explode($xmlTag[$key].'>', $v);
        $v = substr($a[1], 0, strlen($a[1])-2);
        $data[$k][$xmlTag[$key]] = $v;
    }
}
echo '<pre>';
print_r($data);

write_str.xml

<?xml version="1.0" encoding="utf8"?>
<studentcareer>
  <period>
    <starttime>2000</starttime>
    <endtime>2002</endtime>
    <school>培新小学</school>
  </period>
  <period>
    <starttime>2002</starttime>
    <endtime>2006</endtime>
    <school>览表东阳学校</school>
  </period>
  <period>
    <starttime>2006</starttime>
    <endtime>2009</endtime>
    <school>惠来慈云实验中学</school>
  </period>
  <period>
    <starttime>2009</starttime>
    <endtime>2012</endtime>
    <school>惠来一中</school>
  </period>
  <period>
    <starttime>2012</starttime>
    <endtime>2016</endtime>
    <school>华南师范大学</school>
  </period>
</studentcareer>

 不加 pre的效果：