[SOLVED] How do I combine two variables?

[bobleny]

I tried looking this up online, but I don't know what to call it...
I'm sure it is a common problem...

for(int i = 0; i <= numStud; i++)
{
Student stud_i = new Student(numCour);
}

Every time the loop restarts, the "i" in "stud_i", should be replaced with the number it represents....

I don't think I can explain it better than that, so I hope that is good enough. lol

Thanks!

[theonly]

I don't think you can make "i" in stud_i increment since java sees it as a variable name. (java only sees one name that's "stud_i"). It doesn't know that "i" is suppose to be increment. Try to use and array. where stud_i become stud[i]. Of course you will need to change some things around, but yeah.

If not an array just use i instead of stud_i.

[bobleny]

I can't just use "i", because "i" is already defined. This is an error.

I don't know what else to do, I can't use a predefined variable.....

I can't have another array with out some hellish rewrites...

Any other Ideas...

[CaptainMorgan]

Best way to do what you're trying to accomplish, known as dynamic variable naming, is to use HashMaps.

Code:

HashMap<String, Student> map = new HashMap<Student> ();
for (int i = 0; i < numStud; i++) {
  map.put("myObj" + i, new Student());
}

[bobleny]

That will work...

Thanks Captain!

[DonCash]

Please mark this thread as Solved bobleny. Check my sig if you need help.

[bobleny]

Yeah, I was looking for a solved button and I didn't find one, so I thought you didn't have one...

OK, all betters.

Thanks again!

[innocent.crook]

Captain , i am getting the error in the first line , ; expected

HashMap(String, Student)map = new HashMap Student();
for (int i = 0; i < 20; i++) {
map.put("myObj" + i, new Student());
}

i'm using this code

[masijade]

You use greaterThan lessThan signs around those Generics items, not parens.

i.e.

Code:

HashMap<String, Student>

not

Code:

HashMap(String, Student)

and it needs to also appear exactly that way on the right hand side of the equals sign.

[innocent.crook]

m using netbeans..it is showing error "cannot find symbol" for using <>

[masijade]

Probably because you have no "Student" class, which is something that the poster of this question had made himself.

Do you have any idea what a hashmap is? Do you have any idea what Generics is? I hope you can answer yes to both of those questions, since they are to be used in your current homework assignment (help needed regarding LOGIN form), so you have already covered them in your class. Where you paying attention?

[innocent.crook]

i have added key value pairs using hashMap ..n m able to print the keys for the corresponding values.
i want to make the key unique...if a same key is added it will return a boolean false n say ..can't add. and can we add key n value through keyboard??

[masijade]

Quote:

Originally Posted by innocent.crook

i have added key value pairs using hashMap ..n m able to print the keys for the corresponding values.
i want to make the key unique

Use a Set or the containsKey method

Quote:

...if a same key is added it will return a boolean false n say

Attempt to add it to the Set first, or call the containsKey method.

Quote:

..can't add. and can we add key n value through keyboard??

If you write the user interaction, of course, intrinsicaly, no.