Hmm can you plz show me the practical difference to perl?

lanx@nc10-ubuntu:~$ python
Python 2.5.2 (r252:60911, Jan 20 2010, 23:16:55) 
...
>>> str="123"
>>> str+="4"
>>> str
'1234'

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The only thing I can think of are runtime issues :

I've read that in JS  str+="a";str+="b" takes 40% longer than str=str+"a"+"b", because strings have to be copied...

But in perl the second version needs much longer...

  DB<1> $str="";$t=time;for (1..100000) {$str=$str."a"."b"};print time
+-$t
13
  DB<2> $str="";$t=time;for (1..1000000) {$str.="a";$str.="b"};print t
+ime-$t
1

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Actually the same code in python has similar benchmarks

>>> for i in range(1, 1000000):
...   str+="a"+"b"
... 
>>> str=""
>>> for i in range(1, 100000):
...   str=str+"a"+"b"
...

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So where is the practical difference?

Cheers Rolf

UPDATE: Maybe not a good benchmark, since the growing of $str plays a too important role ...

  DB<1> $t=time;for (1..10000000) {$str="";$str.="a"."b";};print time-
+$t
10
  DB<2> $t=time;for (1..10000000) {$str="";$str=$str."a";$str.="b";};p
+rint time-$t
17
  DB<3> $t=time;for (1..10000000) {$str="";$str=$str."a"."b";};print t
+ime-$t
15

[download]

In reply to Re: programming languages and immutable data types by LanX
in thread programming languages and immutable data types by mattk1

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