함수 keys()

keys()

array_keys()

1 Java

자바 HashMap.keySet() 문서를 참고하십시오.

HashMap<String,Object> hm = new HashMap<String,Object>();
hm.put("first", "1");
hm.put("second", "4");

System.out.println( hm.keySet().getClass() );
// class java.util.HashMap$KeySet
System.out.println( hm.keySet() );
// [first, second]

2 JavaScript

JavaScript Object.keys() 문서를 참고하십시오.

var member = { 'ID': '102', 'Name': 'YONEZAWA Akinori', 'Address': 'Naha, Okinawa' };
console.log(Object.keys(member));
// ["ID", "Name", "Address"]

3 PHP

$member = array( 'ID'=>102, 'Name'=>'YONEZAWA Akinori', 'Address'=>'Naha, Okinawa' );
$keys = array_keys($member);
print_r($keys);
# Array
# (
#     [0] => ID
#     [1] => Name
#     [2] => Address
# )

4 Python

• (주의) 순서 바뀜

member = { 'ID' : 102, 'Name' : 'YONEZAWA Akinori', 'Address' : 'Naha, Okinawa' }
print( member.keys() )
# ['Address', 'ID', 'Name']

5 Perl

• (주의) 순서 바뀜

my %month = (
	"January" => "1월",
	"February" => "2월",
	"March" => "3월",
	"April" => "4월",
	"May" => "5월",
	"June" => "6월",
	"July" => "7월",
	"August" => "8월",
	"September" => "9월",
	"October" => "10월",
	"November" => "11월",
	"December" => "12월"
);

foreach my $key (keys %month) {
	print "$key\n";
}
#November
#July
#June
#February
#April
#January
#August
#March
#September
#October
#May
#December

6 Ruby

• (주의) 순서 바뀜

require 'pp'
member = { "ID" => 102, "Name" => "YONEZAWA Akinori", "Address"=> "Naha, Okinawa" }
pp member.keys
# ["Address", "Name", "ID"]

7 같이 보기

• 함수 array_keys_2d()
• 함수 first()
• each_key
• foreach
• Dictionary
• values
• items