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Reputation:

# Random Numbers Squared in 2D array

Posted 03 March 2010 - 02:41 PM

Hey guys.

Im new to c# and this is my first post.

Basically i'm dealing with a 10 rows x 2 columns array. i want to populate the first column with random numbers and the 2nd column with squared values of those numbers.

my code looks like this
```    class Program
{
static void Main(string[] args)
{

const int NUM_ROWS = 10;
const int NUM_COLS = 2;

int[,] randint = new int [NUM_ROWS,NUM_COLS];
Random randNum = new Random();

for (int row = 0; row < randint.GetLength(0); row++)
{
for (int col = 0; col < randint.GetLength(1); col++)
{
int x=randNum.Next(1,100);
int y = x * x;
randint[row,col] = x;

Console.Write(string.Format("{0,5:d} ", randint[row, col]));
}
Console.WriteLine();
}

}
}
```

now this populates both columns with random numbers but i only want one of them, and the other with squared values of those random numbers.

I appreciate any help
Thank you

Is This A Good Question/Topic? 0

## Replies To: Random Numbers Squared in 2D array

### #2 SwiftStriker00

• No idea why my code works

Reputation: 438
• Posts: 1,611
• Joined: 25-December 08

## Re: Random Numbers Squared in 2D array

Posted 03 March 2010 - 02:50 PM

un-nest the for loops. You essentail want to do two passes, first adding some number and then second pass square the numbers
```for(...){
randint [0,i] = random num
}
for(...){
randint[1,i] = randint[0,i] * randint[0,i];
}

```

OR

have a conditional in the inner loop
```if( col == 0){ make random number
}else if( col == 1){
square then number from randint [row,col-1] and save it to randint [row,col]
}

```

This post has been edited by SwiftStriker00: 03 March 2010 - 02:51 PM

Reputation:

## Re: Random Numbers Squared in 2D array

Posted 03 March 2010 - 03:31 PM

SwiftStriker00, on 03 March 2010 - 01:50 PM, said:

un-nest the for loops. You essentail want to do two passes, first adding some number and then second pass square the numbers
```for(...){
randint [0,i] = random num
}
for(...){
randint[1,i] = randint[0,i] * randint[0,i];
}

```

OR

have a conditional in the inner loop
```if( col == 0){ make random number
}else if( col == 1){
square then number from randint [row,col-1] and save it to randint [row,col]
}

```

Swift i cannot thank you enough sir!
i used the if statement and it worked like a charm. again i appreciate it.

### #4 Ferencn

• D.I.C Regular

Reputation: 71
• Posts: 322
• Joined: 01-February 10

## Re: Random Numbers Squared in 2D array

Posted 03 March 2010 - 03:40 PM

Even simpler, use 1 loop:
```class Program
{
static void Main(string[] args)
{
const int NUM_ROWS = 10;
const int NUM_COLS = 2;

int[,] randint = new int [NUM_ROWS,NUM_COLS];
Random randNum = new Random();

for (int row = 0; row < randint.GetLength(0); row++)
{
randint[row,0] = randNum.Next(1,100);
randint[row,1] = randint[row,0]*randint[row,0];

Console.Write(string.Format("{0,5:d} {0,5:d}\n", randint[row,0], randint[row,1]));
}
}
}

```