Javascript vs Ruby Methods

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ARRAYS
RubyJavascript
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a = ["1", "2"]

a.push("3")
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a.map!(&:to_i) # [1, 2, 3]
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a.delete_at(1)
a # [1, 3]
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a.reverse # [3, 1]
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a.unshift(777)




# [777, 3, 1]
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var a = ["1", "2"];

a.push("3");
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a = a.map(function(n) { return parseInt(n, 10); });
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a.splice(1, 1 /* how much */);
a; // [1, 3]
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a.reverse() // [3, 1]
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a.unshift(777); // 777
a; // [777, 3, 1]

/* or in place: */
var b = [3, 1];
[777].concat(b); // [777, 3, 1]
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a = [1, 2, 3]

a.index(2) # 1 
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a.all?{|n| n > 4} # false
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a.any?{|n| n > 2} # true
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a.keep_if{|n| n > 1} # [2, 3]
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var a = [1, 2, 3];

a.indexOf(2); // 1
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a.every(function(n) { return n > 4; }); // false
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a.some(function(n) { return n > 2; });  // true
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a.filter(function(n) { return n > 1;}); // [2, 3]
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a = ["aaa  ", "  bbb", "  ccc  "]

a.map(&:strip)
# ["aaa", "bbb", "ccc"]
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var a = ["aaa  ", "  bbb", "  ccc  "]

a.map(function(x) { return x.trim(); });               // ['aaa', 'bbb', 'ccc']
a.map(Function.prototype.call, String.prototype.trim); // ['aaa', 'bbb', 'ccc']
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a = [1, 2, 3, 4, 5]

a.slice(1..-2)  # [2, 3, 4]
a[1..-2]        # [2, 3, 4]
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var a = [1, 2, 3, 4, 5];


a.slice(1, -1); // [2, 3, 4]
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a = [1, 2, 3]

a.each {|n| puts n}

a.each do |n|
    puts n
end
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for i in 0..(a.length - 1) do
  puts a[i]
end
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var a = [1, 2, 3];





a.forEach(function(n) { console.log(n); })
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for (var i = 0; i < a.length; i++) {
  console.log(a[i]);
}


STRINGS
RubyJavascript
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'hello'.index('e')    # 1
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'hello'.rindex('l')   # 3
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if 'hello'.include? 'lo' then puts 'found' end
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'hello' * 3           # 'hellohellohello'
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'a/b/c'.split('/')    # ['a', 'b', 'c']
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'hello'.indexOf('e')             // 1
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'hello'.lastIndexOf('l')         // 3
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if (~'hello'.indexOf('lo')) { console.log('found'); }
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(new Array(3 + 1)).join('hello') // 'hellohellohello'
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'a/b/c'.split('/')               // ['a', 'b', 'c']


HASH
RubyJavascript
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h = {}
h['a'] = 1
h['b'] = 2

h.each {|key, value| puts "#{key} #{value}" }
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h.keys # ['a', 'b']
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h.has_key?('c') # false
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h.length # 2
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h.delete("b")
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var h = {};
h['a'] = 1;
h['b'] = 2;

for (key in h) { console.log(key, h[key]); }
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Object.keys(h); // ['a', 'b']
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h.hasOwnProperty('c') // false
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Object.keys(h).length // 2
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delete h.b


FUNCTIONS
RubyJavascript
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def plus_5(num = 0) num + 5 end

plus_5     # 5
plus_5(10) # 15

[5, 10, 15].map { |k| plus_5(k) } # [10, 15, 20]
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def f(*args)

  puts args
end
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function plus_5(num) { return (num || 0) + 5; }

plus_5();   // 5
plus_5(10); // 15

[5, 10, 15].map(plus_5); // [10, 15, 20]
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function f() {
  var args = Array.prototype.slice.call(arguments);
  console.log(args);
}


CLASSES
RubyJavascript
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class Person
  attr_accessor :firstName, :lastName

  def initialize(firstName, lastName)
    @firstName = firstName
    @lastName = lastName
  end

  def fullName
    @firstName + " " + @lastName
  end
end

john = Person.new("John", "Malkovic")
john.fullName # "John Malkovic"
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function Person(firstName, lastName) {
  this.firstName = firstName;
  this.lastName = lastName;
}




Person.prototype.fullName = function() {
  return this.firstName + " " + this.lastName;
}


var john = new Person("John", "Malkovic");
john.fullName(); // "John Malkovic"


MATH
RubyJavascript
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[-5, -1, -8].max            # -1
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[-5, 15, 20].reduce(0, &:+) # 30
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Math.max.apply(null, [-5, -1, -8]) // -1
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[-5, 15, 20].reduce(function(sum, value) { return sum + value; }, 0) // 30


MISC..
RubyJavascript
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prng = Random.new()
prng.rand(5..9) # one of [5, 6, 7, 8, 9]
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a, b = b, a # switch a and b
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function rand(a, b) { return Math.floor(Math.random() * (b - a + 1) + a); }
rand(5, 9); // one of [5, 6, 7, 8, 9]
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a = [b, b = a][0]
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