String concatenation.. + vs <<

[Brandon]

So I have the following:

    flash[:success] = 'Your payment has completed. Please contact ' + 

                             @order.seller.name + ' (mobile: ' + 

                             @order.seller.mobile_number + ', email: ' + 

                             @order.seller.email + ')'

Strangely inside this method, I can't seem to do string interpolation and it prints '@order.seller.name'. So that is a strange issue.

But the main thing that puzzles me is should I be replacing + with << here? I read somewhere the performance is better but I really hate seeing << in my code. It just seems ugly and raises my blood pressure for some reason.

[Matt Jones]

On Sunday, 16 March 2014 00:47:45 UTC-4, Brandon wrote:

So I have the following:

    flash[:success] = 'Your payment has completed. Please contact ' + 

                             @order.seller.name + ' (mobile: ' + 

                             @order.seller.mobile_number + ', email: ' + 

                             @order.seller.email + ')'

Strangely inside this method, I can't seem to do string interpolation and it prints '@order.seller.name'. So that is a strange issue.

String interpolation only works with double (") not single (') quotes.

 

But the main thing that puzzles me is should I be replacing + with << here? I read somewhere the performance is better but I really hate seeing << in my code. It just seems ugly and raises my blood pressure for some reason.

If you're concatenating a LOT of strings, << is definitely preferable - a + b + c + d generates three intermediate String objects which need to be GCed, while a << b << c << d doesn't.

--Matt Jones 

[Brandon]

Thanks Matt! It is the single quotes which I'm about to convert back to double quotes!!

[Colin Law]

On 16 March 2014 14:21, Matt Jones <al2...@gmail.com> wrote:
>
>
> On Sunday, 16 March 2014 00:47:45 UTC-4, Brandon wrote:
>>
>> So I have the following:
>>
>> flash[:success] = 'Your payment has completed. Please contact ' +
>> @order.seller.name + ' (mobile: ' +
>> @order.seller.mobile_number + ', email: ' +
>> @order.seller.email + ')'
>>
>> Strangely inside this method, I can't seem to do string interpolation and
>> it prints '@order.seller.name'. So that is a strange issue.
>>
>
> String interpolation only works with double (") not single (') quotes.

But since @order.seller.name is not inside quotes that does not
explain why @order.seller.name is not interpreted.

Colin

>
>>
>> But the main thing that puzzles me is should I be replacing + with <<
>> here? I read somewhere the performance is better but I really hate seeing <<
>> in my code. It just seems ugly and raises my blood pressure for some reason.
>
>
> If you're concatenating a LOT of strings, << is definitely preferable - a +
> b + c + d generates three intermediate String objects which need to be GCed,
> while a << b << c << d doesn't.
>
> --Matt Jones
>

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