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Topic: $ifequal() and $ifgreater() doubt (Read 5220 times) previous topic - next topic
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$ifequal() and $ifgreater() doubt

I need to detect if an album tag contains a certain letter, say z

For a given track, by using $strchr(%album%,z) I can note that theres is a z char at position 7

However, for the same track
- if I use $ifequal(strchr(%album%,z),0,no,yes), the (wrong) result is no
- if I use $ifgreater(strchr(%album%,z),0,yes,no), the (wrong) result is no

Tracks that do not have a z evaluate (rightly) to no

What is wrong with the logic?

$ifequal() and $ifgreater() doubt

Reply #1 –
you forgot to put $ before strchr

the correct expression would be $ifgreater($strchr(%album%,z),0,yes,no)

$ifequal() and $ifgreater() doubt

Reply #2 –
Quote from: adf on
you forgot to put $ before strchr

the correct expression would be $ifgreater($strchr(%album%,z),0,yes,no)


Of course!
Can't believe it myself.
Thanks.

$ifequal() and $ifgreater() doubt

Reply #3 –
Just to mention it, there is a $strstr alternative, so you need no numerical comparation:

$if($strstr($lower(%album%),z),yes,no)

($strstr is case sensitive, maybe you wouldn't need the $lower)

$ifequal() and $ifgreater() doubt

Reply #4 –
This is optimized, i think =)

$if($strchr(%album%,z),yes,no)

$ifequal() and $ifgreater() doubt

Reply #5 –
Squeller's and joule's answers are taking advantage of the fact that $strchr() and $strstr() have a numeric and also a logical result - right?
(Since in this case the character's position doesn't matter, by using the logical result the expression may be simpler).

A doubt:
Since a character may be regarded as a string with only one element, why $strchr()? Wouldn't $strstr() suffice?

$ifequal() and $ifgreater() doubt

Reply #6 –
Perhaps correct. I guess $strstr is a faster function and therefore better to use?

$ifequal() and $ifgreater() doubt

Reply #7 –
Quote from: pstrg on
Squeller's and joule's answers are taking advantage of the fact that $strchr() and $strstr() have a numeric and also a logical result - right?
Correct.

Quote
Perhaps correct. I guess $strstr is a faster function and therefore better to use?

I have no odea. Do 10000 strstr's and strchr's, compare calculation times and let us know

$ifequal() and $ifgreater() doubt

Reply #8 –
Quote from: Squeller on
I have no odea. Do 10000 strstr's and strchr's, compare calculation times and let us know


Compilation:
10000x $strchr: 315.5751359460 ms
10000x $strstr: 332.9715368853 ms

Execution:
10000x $strchr: 86.4468266917 ms
10000x $strstr: 86.9423837387 ms

This is just one of ten speed tests. There are no coherent results as to which function is faster.

Album: Fatboy Slim - Halfway Between The Gutter And The Stars (FLAC)
AMD Athlon 2800+, foobar2000 0.9.4

Nothing is impossible if you don't need to do it yourself.

$ifequal() and $ifgreater() doubt

Reply #9 –
thx

$ifequal() and $ifgreater() doubt

Reply #10 –
Just realized $strchr is just for one character (it only checks the first character of the 2nd argument), wheras $strstr can be used for comparing complete strings, but case sensitive.

$ifequal() and $ifgreater() doubt

Reply #11 –
Quote from: Squeller on
Just realized $strchr is just for one character (it only checks the first character of the 2nd argument), wheras $strstr can be used for comparing complete strings, but case sensitive.

That's why I wondered about the reason for the existence of $strchr(), since $strstr() suffices and, as measured by Silverlight, is just as efficient.
Sure, quod abundat non nocet - just curious.