How to replace a digit in a string using a regular expression?

Question

ruby

This question may seem very, very strange, but it is necessary to do exactly according to these actions. I took it as an example JavaScript, but you can do it on any other. The main thing is to follow the rules
. There is a variable. It is a = 0;
necessary to make it a line with words. Approximately so:
a = a.replace(0, /* регулярное выражение */ );
Here actually and a problem. What regular expression should be used to replace it with the words "Hello world"
In fact, you can simply do this: a = "Hello world";
But the key point is that you need to do this without using quotes. None at all! This is where the idea of ​​using regular expressions popped into my head.
But if there is another way, please tell me how. Most importantly, you can't use quotes .

Answer 1

It's all right?
>>a = 0
=> 0
>> a = a.to_s.sub('0',%{hello world})
=> "hello world"
>> a
=> "hello world"
a = 123
=> 123
> > a = a.to_s.gsub(/\d+/,%{hello world})
=> "hello world"
>> a
=> "hello world"