Two dimensional array problem

[Juggernaut]

I have a two dimensional array, [12][31], and I have it made as a
calender where the days are filled with some information. But some
months, like february only has 28 days so I havent filled 29 30 and
31. But now I want to make some calculations on these numbers, and
divide them by all the days. But the problem is they also count the
array fields like february 29 , 30 and 31 wich is empty..I tried a for
loop where if col < table[row].length && table[row][col] != null. But
that didnt work, how can I do this?

Someone suggested for me to try
yourArray[1] = new int SomeType[28];

But java didnt accept this.

Any advice would be gratefull.

 

[Juggernaut]

Nevermind this one..

 

[Marco Schmidt]

Juggernaut:

Someone suggested for me to try
yourArray[1] = new int SomeType[28];

But java didnt accept this.

Try

yourArray[1] = new int[28];

If yourArray is of type int[][], that should work.

I don't know what exactly you are trying to do, but it seems like you
could profit from encapsulating the array and provide methods like
getDaysPerMonth(int month). That may make the code more readable and
maintainable.

Regards,
Marco

 

[Juggernaut]

Thats what I first did, I had a switch.
But what it did was fill for example february with 28 values, and left the 3
left cells clear. But I dont want those remaining cells to be clear, I want
them to not exist. Thereby having a ragged array.

Juggernaut:

Someone suggested for me to try
yourArray[1] = new int SomeType[28];

But java didnt accept this.

Try

yourArray[1] = new int[28];

If yourArray is of type int[][], that should work.

I don't know what exactly you are trying to do, but it seems like you
could profit from encapsulating the array and provide methods like
getDaysPerMonth(int month). That may make the code more readable and
maintainable.

Regards,
Marco

 

[Jon A. Cruz]

But I dont want those remaining cells to be clear, I want
them to not exist. Thereby having a ragged array.

Another common term is "jagged"

 

[Andrew Hobbs]

Thats what I first did, I had a switch.
But what it did was fill for example february with 28 values, and left the 3
left cells clear. But I dont want those remaining cells to be clear, I want
them to not exist. Thereby having a ragged array.

To specifically answer your question how about

int[][] year = new int[][] { new int[31], new int[28], new int[31],
new int[30], new int[31], new int[30], new int[31],
new int[31], new int[30], new int[31], new int[30],
new int[31], };

That will give you a jagged array.

It will also give you difficult to read code. Eminently forgettable code and
probably rather fragile code. It also doesn
t make provision for leap years.

As Marco said why not encapsulate your code.

Why not write a day class which accepts whatever values you need and does
the calculations you want to do. Then write a month class which holds day
objects. These can validate the number of days, make provision for 29 vs 28
days in February depending upon year etc. Then a year class holds month
objects, providing names to months etc. By providing names to objects you
will find it much easier to see what is going on and to rectify problems.

Andrew


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Andrew Hobbs PhD

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Australia

61 8 9246 2026
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Juggernaut:

Someone suggested for me to try
yourArray[1] = new int SomeType[28];

But java didnt accept this.

Try

yourArray[1] = new int[28];

If yourArray is of type int[][], that should work.

I don't know what exactly you are trying to do, but it seems like you
could profit from encapsulating the array and provide methods like
getDaysPerMonth(int month). That may make the code more readable and
maintainable.

Regards,
Marco