Perl与JS的对比分析(数组、哈希)

@goods = qw/pen pencil/; 
pop(@goods); # @goods 变成 (pen) 
push(@goods, 'brush'); # @goods 变为 (pen, brush) 

pop @goods; # @goods 变成 pen 
push @goods, 'brush'; # @goods 变为 (pen, brush) 

@goods = qw/pen pencil/; 
 
# 将数组变量赋值给一个标量变量 
$len = @goods; 
 
# 使用scalar函数 
$len = scalar(@goods); 
 
# 最后一个元素的索引加1 
$len = $#goods + 1; 

@goods = qw/pen pencil brush/; 
 
# 默认的$_ 
foreach (@goods) { 
 print "$_"."\n"; 
} 
 
# 自定义变量 
foreach $item (@goods) { 
 print "$item"."\n"; 
} 

['pen', 'pencil', 'brush'].forEach(function(item) { 
  console.log(item) 
}) 

%person = ( 
 name => 'Jack', 
 age => 30, 
); 
@k = keys %person; # (name, age) 
@v = values $person; # ('Jack', 30) 

person = { 
 name: 'Jack', 
 age: 30 
} 
Object.keys(person) // ['name', 'age'] 

%person = ( 
 name => 'Jack', 
 age => 30, 
); 
$len = keys %person; # 2 

function getObjLen(obj) { 
  var len = 0 
  for (var a in obj) { 
    if (obj.hasOwnProperty(a)) 
    len++ 
  } 
  return len 
} 
 
var person = { 
  name: 'Jack', 
  age: 30 
} 
getObjLen(person) // 2

%person = ( 
 name => 'Jack', 
 age => 30, 
); 
 
# 方式1 
while ( ($k, $v) = each %person ) { 
 print "$k: $v"."\n"; 
} 
 
# 方式2 
@keys = keys %person; 
foreach(@keys) { 
 print "$_: ".$person{$_}."\n"; 
} 

%person = ( 
 name => 'Jack', 
 age => 30, 
); 
if (exists $person{ndame}) { 
 print 'yes'; 
} else { 
 print 'no'; 
} 

%person = ( 
 name => 'Jack', 
 age => 30, 
); 
delete $person{'name'}; 

%person = ( 
 name => 'Jack', 
 age => 30, 
); 
@arr = %person; # 将哈希转成数组 变成了('name', 'Jack', 'age', 30) 

@nums = qw/zero 0 one 1 two 2/; 
%hash = @nums; 
while( ($k, $v) = each %hash ) { 
 print "$k: $v\n"; 
}