Re: How to check for key existence in a table (for the lazy programmer) ?

["Soni L." <fakedme@...>]

On 31/01/15 08:45 AM, Bertrand Mansion wrote:
> In Lua programs, I often see code like the following:
>
>    if host.devices and host.devices.bridge and host.devices.bridge.friendlyName then
If Lua could use assignments as expressions, we could have things like this:

local temp;
if (temp = host.devices) and (temp = temp.bridge) and (temp = 
temp.friendlyName) then

Which's _WAY_ faster.

(Does anyone know if moonscript or something supports this?)
> In Php, I have seen this:
>
>    if (isset($host['devices']['bridge']['friendlyName']))
>
>
> In Python, I have seen this:
>
>    try:
>      if host['devices']['bridge']['friendlyName']:
>        ...
>    except KeyError:
>      pass
>
> Are there other ways in Lua to check for a key existence ?

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