When reading into this issue somebody suggested === would be faster than ==,
I just finished running a very basic benchmark comparing == vs === as far as
speed is concerned (string comparison). Unsurprisingly there isn't any speed
difference, however the uncertainty of the results in === was far bigger
(0.05 s with == and 0.3 s with ===), could anybody check whether this
difference is reproducible or whether this is only some random problem with
my system. (Tested with chromium on mac). I ran the following script 10
times for both == and ===, it's might be a bit simplistic, but there would
have any big difference it should have come out.
<script>
start = (new Date()).getTime();
string = "Lorem Ipsum is simply dummy text of the printing and typesetting
industry. Lorem Ipsum has been the industry's standard dummy text ever since
the 1500s, when an unknown printer took a galley of type and scrambled it to
make a type specimen book. It has survived not only five centuries, but also
the leap into electronic typesetting, remaining essentially unchanged. It
was popularised in the 1960s with the release of Letraset sheets containing
Lorem Ipsum passages, and more recently with desktop publishing software
like Aldus PageMaker including versions of Lorem Ipsum.";
string2 = "Lorem Ipsum is simply dummy text of the printing and typesetting
industry. Lorem Ipsum has been the industry's standard dummy text ever since
the 1500s, when an unknown printer took a galley of type and scrambled it to
make a type specimen book. It has survived not only five centuries, but also
the leap into electronic typesetting, remaining essentially unchanged. It
was popularised in the 1960s with the release of Letraset sheets containing
Lorem Ipsum passages, and more recently with desktop publishing software
like Aldus PageMaker including versions of Lorem Ipsum.";
for(i=0;i<10000;i++){
if(string===string2){
string=string+" ";
string2=string2+" ";
}
}
stop = (new Date()).getTime();
console.log(stop-start);
</script>
David Mulder
On Mon, Mar 15, 2010 at 4:20 PM, David Mulder <[email protected]>wrote:
> When reading into this issue somebody suggested === would be faster than
> ==, I just finished running a very basic benchmark comparing == vs === as
> far as speed is concerned (string comparison). Unsurprisingly there isn't
> any speed difference, however the uncertainty of the results in === was far
> bigger (0.05 s with == and 0.3 s with ===), could anybody check whether this
> difference is reproducible or whether this is only some random problem with
> my system. (Tested with chromium on mac). I ran the following script 10
> times for both == and ===, it's might be a bit simplistic, but there would
> have any big difference it should have come out.
>
> <script>
> start = (new Date()).getTime();
> string = "Lorem Ipsum is simply dummy text of the printing and typesetting
> industry. Lorem Ipsum has been the industry's standard dummy text ever since
> the 1500s, when an unknown printer took a galley of type and scrambled it to
> make a type specimen book. It has survived not only five centuries, but also
> the leap into electronic typesetting, remaining essentially unchanged. It
> was popularised in the 1960s with the release of Letraset sheets containing
> Lorem Ipsum passages, and more recently with desktop publishing software
> like Aldus PageMaker including versions of Lorem Ipsum.";
> string2 = "Lorem Ipsum is simply dummy text of the printing and typesetting
> industry. Lorem Ipsum has been the industry's standard dummy text ever since
> the 1500s, when an unknown printer took a galley of type and scrambled it to
> make a type specimen book. It has survived not only five centuries, but also
> the leap into electronic typesetting, remaining essentially unchanged. It
> was popularised in the 1960s with the release of Letraset sheets containing
> Lorem Ipsum passages, and more recently with desktop publishing software
> like Aldus PageMaker including versions of Lorem Ipsum.";
> for(i=0;i<10000;i++){
> if(string===string2){
> string=string+" ";
> string2=string2+" ";
>
> }
> }
>
> stop = (new Date()).getTime();
> console.log(stop-start);
> </script>
>
> David Mulder
>
> On Mon, Mar 15, 2010 at 4:03 PM, Owen Taylor <[email protected]> wrote:
>
>> On Sat, 2010-03-13 at 13:21 +1100, Lex Hider wrote:
>>
>> > However, this one (== vs ===) does seem to be a very worthwhile change
>> > to the style guide to consider.
>> > Wouldn't it be clearer if code depending on (0 != null but undefined
>> > ==null) be made explicit?
>>
>> I've (in the past) read what Crockford has to say on the issue, and
>> didn't find it convincing.
>>
>> Yes, the coercion behavior of the standard '==' is surprising
>> at times (strings to numbers in particular), but that only happens
>> of you are comparing items that are in fact of different types. Which is
>> generally not good programming practice.
>>
>> But if you use '===', then you have to have an accurate mental model of
>> where javascript uses 'undefined' and where it uses 'null', and that's
>> hard and obscure.
>>
>> And also, you make the code look strange and intimidating.
>>
>> So, my rule is that you should only use === and !== if it actually makes
>> a difference and you should try to avoid situations where it actually
>> makes a difference.
>>
>> - Owen
>>
>>
>>
>> _______________________________________________
>> gnome-shell-list mailing list
>> [email protected]
>> http://mail.gnome.org/mailman/listinfo/gnome-shell-list
>>
>
>
_______________________________________________
gnome-shell-list mailing list
[email protected]
http://mail.gnome.org/mailman/listinfo/gnome-shell-list
