我正在解析
XML文件并尝试访问
XML文件中的值.
#!/usr/bin/perl -w
use strict;
use XML::Twig;
my $file = 'files/camelids.xml';
print "File :: $file\n";
my $twig = XML::Twig->new();
$twig->parsefile($file);
# print "twig :: $twig\n";
my $root = $twig->root;
# print "root :: $root\n";
my $num = $root->children('species');
print "num :: $num\n\n\n";
print $root->children('species')->first_child_text('common-name');
示例XML文件是：
<?xml version="1.0"?>
<camelids>
<species name="Camelus bactrianus">
<common-name>Bactrian Camel</common-name>
<physical-characteristics>
<mass>450 to 500 kg.</mass>
<appearance>
<in-appearance>
<inside-appearance>This is in inside appearance</inside-appearance>
</in-appearance>
</appearance>
</physical-characteristics>
</species>
</camelids>
输出是：
File :: files/camelids.xml num :: 1 Can't call method "first_child_text" without a package or object reference at xml-twig_read.pl line 19.
如何解决这个问题？
这行代码是否有任何错误,需要进行任何修改(这里我试图将通用名称作为Bactrian Camel)
print $root->children('species')->first_child_text('common-name');
解决方法
将最后一行更改为
my @nums = $root->children('species');
print "num :: @nums\n\n\n";
foreach my $num (@nums) {
print $num->first_child_text('common-name');
}
children返回一个数组,因此你需要运行它.
要帮助调试,请尝试以下方法：
my @nums = $root->children('species');
use Data::Dumper; #More debug information like this than a normal print
print Dumper @nums;
foreach my $num (@nums) {
print $num->first_child_text('common-name');
}