So i have this code, ran 3 times on 3 differents files of 3 lines each. My problem is that it keeps returning the same lines for each file.

Ex : If line 1 is returned from file 1, it'll return line 1 form file 2 and file 3.

Any idea?

not sure what language thats in (i think its C#) but anyways it sounds like you are not seeding a random value.

in C its done as so.



also with such small choice of lines you have about a 33.333~ chance of getting the same line. which is pretty great so you may have to run your application a couple times to see changes, but i do believe its because of the lack of seeding.

This post was edited by AbDuCt on Dec 9 2012 10:53am

Yup it's C#. I've never had problems with the Random class before :0

yea idk i dont have visual studios where i am atm so i cant help much.

your implementation looks correct. have you tried to set a breakpoint inside the function and examine that each variable holds at each line? what does text.length return? i assume its returning the LENGTH of the string at text[0].

i think the method you want to be using is .count

http://msdn.microsoft.com/en-us/library/system.string.aspx



string.Count returns the total number of elements in a string array. which is what i think you intended (because each string is in its own element).

edit:: also you dont need that else clause there. just do this.



if the if statement doesnt trigger it would return "" anyways. and if it does trigger it returns the text. does the exact same thing but removes like 4 lines.

This post was edited by AbDuCt on Dec 9 2012 11:51am

Lenght return the lenght of the array. I could compare that to sizeof(array)/sizeof(array_type) in C++

you sure. msds claims



and



i believe you would have to use .Count in order to get a random value to use as an element to return beecause .Length returns the number of characters inside the current element.

ex:

text[0] = "hai"
text[1] = " bai"

text.Length() would return 3

and text.Count would return 2

because text (aka text[0]... text is a pointer to the first element of the string array) has 3 characters in it.

where as text.Countt returns the total number of elements in the array.

it might be returnng 1 for every file because of some weird segfault where you are trying to return a string element that doesnt exist.

as in if your function would pick 3 as the random value and try to return text[3]. it would segfault because there is no allocated memory at that address space.

at least i think thats whats happening here

This post was edited by AbDuCt on Dec 9 2012 11:58am

Problem solved. Declared r as a field of my form. Got him out of the function.

The random class uses a seed (defaults to current datetime). I suspect that if this code was running fast enough then the same seed was injected resulting in consistent random results.

This. Try using DateTime.Ticks method to seed the Random object.

I didn't bother reading the other replies... so this was probably already said... but...

When you declare the random object... it creates a time seed... based on the current time... then when it generates a random number... it bases it off of that... so... if you declare to random objects beside each other... and call both of their "Next" functions... they will likely generate the same number.. HOWEVER... if you call the "Next" function twice on the same object... it will generate a new number based on the seed... so it will generate two different numbers.

TL;DR
Declare your Random object outside the function, and just call the Next() function on it.