Enum Methods comparison in Ruby/ Javascript and Elixir

all?

The all? method in Ruby returns a boolean value (true/false) if all the objects in the list either return true or satisfies the block condition.

Ruby

Enumerable#all?

No block:

>> [ true, "dog", "bear", 19 ].all?
=> true
>> [ nil, true, "hello" ].all?
=> false

With a block:

>> %w(cat dog squirrel bear).all? { |word| word.length >= 3 }
=> true
>> %w(cat dog squirrel bear).all? { |word| word.length <= 3 }
=> false

Elixir

Enum.all? No block:

>> Enum.all?([ true, "dog", "bear", 19 ])
true
>> Enum.all?([ nil, true, "hello" ])
false

With a block/fn:

>> Enum.all?(["cat", "dog", "squirrel", "bear"], fn word -> String.length(word) >= 3 end)
=> true
>> Enum.all?(["cat", "dog", "squirrel", "bear"], fn word -> String.length(word) <= 3 end)
=> false

Javascript

Array.prototype.every()

Only with callback support:

> [ true, "dog", "bear", 19 ].every(x => x)
true
> [null, true, "hello" ].every(x => x)
false

> ["cat", "dog", "squirrel", "bear"].every(word => word.length >= 3)
true
> ["cat", "dog", "squirrel", "bear"].every(word => word.length <= 3)
false

any?

Ruby

The any? method in Ruby returns a boolean value (true/false) if all the objects in the list either return false or fail to satisfy the block condition.

Enumerable#any?

No block:

>> [ true, "dog", "bear", 19 ].any?
=> true
>> [ nil, true, "hello" ].any?
=> false
>> [ nil ].any?
=> false
>> [ ].any?
=> false

With a block:

>> %w(cat dog squirrel bear).any? { |word| word.length >= 3 }
=> true
>> %w(cat dog squirrel bear).any? { |word| word.length > 100 }
=> false

Elixir

Enum.any? No block:

>> Enum.any?([ true, "dog", "bear", 19 ])
true
>> Enum.any?([ nil, true, "hello" ])
true
>> Enum.any?([ nil ])
false
Enum.any?([ ])
false

With a block/fn:

>> Enum.any?(["cat", "dog", "squirrel", "bear"], fn word -> String.length(word) >= 3 end)
=> true
>> Enum.any?(["cat", "dog", "squirrel", "bear"], fn word -> String.length(word) > 100 end)
=> false

Javascript

Array.prototype.some()

Only with callback support:

> [ true, "dog", "bear", 19 ].some(x => x)
true
> [null, true, "hello" ].some(x => x)
false
> [ null ].some(x => x)
false
> [ null, false ].some(x => x)
false
> [  ].some(x => x)
false

> ["cat", "dog", "squirrel", "bear"].some(word => word.length > 3)
true
> ["cat", "dog", "squirrel", "bear"].some(word => word.length > 100 )
false

collect / map

detect / find