Perl与JS的对比分析(数组、哈希)

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@goods = qw/pen pencil/;

pop(@goods); # @goods 变成 (pen)

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

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pop @goods; # @goods 变成 pen

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

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@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;

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@goods = qw/pen pencil brush/;

# 默认的$_

foreach (@goods) {

 print "$_"."\n";

}

# 自定义变量

foreach $item (@goods) {

 print "$item"."\n";

}

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

  console.log(item)

})

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%person = (

 name => 'Jack',

 age => 30,

);

@k = keys %person; # (name, age)

@v = values $person; # ('Jack', 30)

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person = {

 name: 'Jack',

 age: 30

}

Object.keys(person) // ['name', 'age']

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%person = (

 name => 'Jack',

 age => 30,

);

$len = keys %person; # 2

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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

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%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";

}

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%person = (

 name => 'Jack',

 age => 30,

);

if (exists $person{ndame}) {

 print 'yes';

} else {

 print 'no';

}

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%person = (

 name => 'Jack',

 age => 30,

);

delete $person{'name'};

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%person = (

 name => 'Jack',

 age => 30,

);

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

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@nums = qw/zero 0 one 1 two 2/;

%hash = @nums;

while( ($k, $v) = each %hash ) {

 print "$k: $v\n";

}