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"; }