英文:
Unable to find if one item exists in array of items and return the necessary message in Perl
问题
我有一组ID。我有一个ID，我想在Perl中查找该ID是否存在于ID数组中。
我尝试了以下代码：
my $ids = [7,8,9];
my $id = 9;
foreach my $new_id (@$ids) {
if ($new_id == $id) {
print 'yes';
} else {
print 'no';
}
}
我得到的输出是：
nonoyes
相反，我希望只获得以下输出：
yes
因为ID存在于ID数组中。
有人可以帮忙吗？
提前感谢。
英文:
I have array of IDs. I have one ID which I want to find if that ID exists in the array of IDs in Perl
I tried the following code:
my $ids = [7,8,9];
my $id = 9;
foreach my $new_id (@$ids) {
if ($new_id == $id) {
print 'yes';
} else {
print 'no';
}
}
I get the output as:
nonoyes
Instead I want to get the output as only:
yes
Since ID exists in array of IDs
Can anyone please help ?
Thanks in advance
答案1
得分: 5
my $ids = [7,8,9];
my $id = 9;
if (grep $_ == $id, @ids) {
print $id. " 在 ids 数组中";
} else {
print $id. " 不在数组中";
}
英文:
my $ids = [7,8,9];
my $id = 9;
if (grep $_ == $id, @ids) {
print $id. " is in the array of ids";
} else {
print $id. " is NOT in the array";
}
答案2
得分: 3
只需删除 else 部分并在找到匹配项后中断循环：
my $flag = 0;
foreach my $new_id (@$ids) {
if ($new_id == $id) {
print 'yes';
$flag = 1;
last;
}
}
if ($flag == 0){
print "no";
}
另一种选项是使用哈希表：
my %hash = map { $_ => 1 } @$ids;
if (exists($hash{$id})){
print "yes";
}else{
print "no";
}
英文:
You just need to remove the else part and break the loop on finding the match:
my $flag = 0;
foreach my $new_id (@$ids) {
if ($new_id == $id) {
print 'yes';
$flag = 1;
last;
}
}
if ($flag == 0){
print "no";
}
Another option using hash:
my %hash = map { $_ => 1 } @$ids;
if (exists($hash{$id})){
print "yes";
}else{
print "no";
}
答案3
得分: 2
use List::Util qw(any); # 核心模块
my $id = 9;
my $ids = [7, 8, 9];
my $found_it = any { $_ == $id } @$ids;
print "yes" if $found_it;
英文:
use List::Util qw(any); # core module
my $id = 9;
my $ids = [7,8,9];
my $found_it = any { $_ == $id } @$ids;
print "yes" if $found_it;
答案4
得分: 0
以下是翻译好的部分：
下面的代码段应该满足您的要求
use strict;
use warnings;
my $ids = [7,8,9];
my $id = 9;
my $flag = 0;
map{ $flag = 1 if $_ == $id } @$ids;
print $flag ? 'yes' : 'no';
注意：也许 `my @ids = [7,8,9];` 是将数组分配给变量的更好方式
英文:
The following piece of code should cover your requirements
use strict;
use warnings;
my $ids = [7,8,9];
my $id = 9;
my $flag = 0;
map{ $flag = 1 if $_ == $id } @$ids;
print $flag ? 'yes' : 'no';
NOTE: perhaps my @ids = [7,8,9]; is better way to assign an array to variable
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