Ruby |
Javascript |
|
|
Arrays |
a = ["1", "2"]
a.push("3")
a.map!(&:to_i) # [1, 2, 3]
a.delete_at(1)
a # [1, 3]
a.reverse! # [3, 1]
a.unshift(777) # [777, 3, 1]
a.last # [1]
|
var a = ["1", "2"];
a.push("3");
a = a.map(function(n) { return parseInt(n, 10); });
a.splice(1, 1 /* how much */);
a; // [1, 3]
a.reverse() // [3, 1]
a.unshift(777); // 3
a; // [777, 3, 1]
/* or in place: */ var b = [3, 1];
[777].concat(b); // [777, 3, 1]
a.slice(-1)[0]; // 1
/* or */ a[a.length - 1]; // 1
|
a = [1, 2, 3]
a.index(2) # 1
a.all?{|n| n > 4} # false
a.any?{|n| n > 2} # true
a.keep_if{|n| n > 1} # [2, 3]
|
var a = [1, 2, 3];
a.indexOf(2); // 1
a.every(function(n) { return n > 4; }); // false
a.some(function(n) { return n > 2; }); // true
a.filter(function(n) { return n > 1;}); // [2, 3]
|
a = ["aaa ", " bbb", " ccc "]
a.map(&:strip) # ["aaa", "bbb", "ccc"]
|
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']
|
a = [1, 2, 3, 4, 5]
a.slice(1..-2) # [2, 3, 4]
a[1..-2] # [2, 3, 4]
|
var a = [1, 2, 3, 4, 5];
a.slice(1, -1); // [2, 3, 4]
|
a = [1, 2, 3]
a.each {|n| puts n}
a.each do |n|
puts n
end
for i in 0..(a.length - 1) do
puts a[i]
end
|
var a = [1, 2, 3];
a.forEach(function(n) { console.log(n); })
for (var i = 0; i < a.length; i++) {
console.log(a[i]);
}
|
Strings |
'hello'.index('e') # 1
'hello'.rindex('l') # 3
if 'hello'.include? 'lo' then puts 'found' end
'hello' * 3 # 'hellohellohello'
'a/b/c'.split('/') # ['a', 'b', 'c']
|
'hello'.indexOf('e') // 1
'hello'.lastIndexOf('l') // 3
if (~'hello'.indexOf('lo')) { console.log('found'); }
(new Array(3 + 1)).join('hello') // 'hellohellohello'
'a/b/c'.split('/') // ['a', 'b', 'c']
|
Hash |
h = {}
h['a'] = 1
h['b'] = 2
h.each {|key, value| puts "#{key} #{value}" }
h.keys # ['a', 'b']
h.has_key?('c') # false
h.length # 2
h.delete("b")
|
var h = {};
h['a'] = 1;
h['b'] = 2;
for (key in h) { console.log(key, h[key]); }
Object.keys(h); // ['a', 'b']
h.hasOwnProperty('c') // false
Object.keys(h).length // 2
delete h.b
|
Functions |
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]
|
function plus_5(num) { return (num || 0) + 5; }
plus_5(); // 5
plus_5(10); // 15
[5, 10, 15].map(plus_5); // [10, 15, 20]
|
def f(*args)
puts args
end
|
function f() {
var args = Array.prototype.slice.call(arguments);
console.log(args);
}
|
sample_func
def sample_func
puts "Hello World"
end
# => NameError: undefined local
# variable or method `sample_func'
|
sample_func();
function sample_func() {
console.log("Hello World");
};
// => Hello World
|
Classes |
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"
|
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 |
[-5, -1, -8].max # -1
[-5, 15, 20].reduce(0, &:+) # 30
|
Math.max.apply(null, [-5, -1, -8]) // -1
[-5, 15, 20].reduce(function(sum, value) { return sum + value; }, 0) // 30
|
Other |
prng = Random.new()
prng.rand(5..9) # one of [5, 6, 7, 8, 9]
a, b = b, a # switch a and b
|
function rand(a, b) { return Math.floor(Math.random() * (b - a + 1) + a); }
rand(5, 9); // one of [5, 6, 7, 8, 9]
a = [b, b = a][0] // do not try at home :-)
|
