## Context

You have an array of hashes and want to check if all elements are satisfying a condition.

## TIL

You might want to do this in Ruby:

```ruby
objects.all? { _1[:amount] > 10 } 
```

In this case, you should remember according to [with the documentation](https://docs.ruby-lang.org/en/3.0.0/Enumerable.html) `.all?` might return true in this case:

```ruby
[].all? 
# returns true 
```  

So this thing might happen

```ruby
array = []

array.all? { _1[:amount] > 1}
# will return true

array.all? { _1[:this_key_does_not_exists] > 1}
# will return true
```

## Quick fix

Use 

```ruby 
array.present? && array.all? { _1[:key_does_not_exist] > 1}
```

Explanation: 

First check if the array is not empty and then try to apply the condition to all elements.

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Published at: 2021-12-10 | Author: Lucian Ghinda