Why is the last row of my array filled with random numbers?

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I am trying to make a 10x10 array filled with 0's and then printing it but the last row is not filling up with 0's.

#include <iostream>

using namespace std;

int main()
{

int table[9][9];
int height = 9;
int width = 9;

for(int i=0; i<=width; i++){
    for(int j=0; j<=height; j++){
        table[i][j] = 0;
    }
}

for(int i=0; i<=9; i++){
    for(int j=0; j<=9; j++){
            cout << table[i][j] << " ";
    }
    cout << endl;
}
}

Why does this make my last row to come out as:

0 9 2 9 10 9 4201024 6422336 6422420 4199045

Instead of 0 like the rest of the rows?

Arrays in C++ are indexed from 0. That means if you have an array of size 9, it contains indices 0-8. If you check the index arr[9], you get undefined behavior. The last index of any array in C++ is its size minus 1. In your loops, you heck the index equal to the size of the array. This is undefined behavior. Sometimes you might get a segfault, sometimes you will get numbers, but it is never defined. If you change your loops to:

for(int i = 0; i<9; i++) 

instead of:

for(int i = 0; i<=9; i++)

Then you won't see this behavior. If you want to make a 10x10 array, change your array declaration to this:

int table[10][10];

and change your for loop to iterate from 0 to 9.

Array Pick Random, Enter your list's items, one at a time, in the box above (just enter some text and hit enter). For example I want to select a random element in last row of a matrix. array of bytes filled with random numbers, and NextDouble returns a random  Create Arrays of Random Numbers MATLAB ® uses algorithms to generate pseudorandom and pseudoindependent numbers. These numbers are not strictly random and independent in the mathematical sense, but they pass various statistical tests of randomness and independence, and their calculation can be repeated for testing or diagnostic purposes.

Your array size is 10, which means your index range is from 0 to 9. You are attempting to access an array element at index 10 which is out of range. Here's what's happening.

When storage for an array is allocated, the memory locations for the elements are contiguous, meaning that they are adjacent to each other in RAM. When you attempt to access an array element with an index that is not within the bounds of the array, you will get whatever happens to be in that particular location of RAM at that time, which could be anything.

Referencing the image above, if your array is to store 4 elements, your index range will be from 0 to 3. So, if you attempt to access an element at index 4, you will get a random value.

range - Manual, range — Create an array containing a range of elements The function will generate an array of integers even if your numerical Merge the new columns which were created with the final columns array. If you're looking to fill an array to get a hash with 0-9 numerical values, using foreach($alphabet2 as $row){ Random numbers between 1 and 100: 5. Random number between 0 AND 10: 6. Random integers that range from from 0 to n: 7. Random.nextInt(n) returns a distributed int value between 0 (inclusive) and n (exclusive). 8. Round Java float and double numbers using Math.round: 9. Randomizer: 10. nextDouble() and nextGaussian() in java.util.Random: 11

Indices start with 0. So your loop should be changed from

for(int i=0; i<=width; i++) to for(int i=0; i<width; i++).

Currently you are printing out one additional row that does not belong to your array.

The reason why it appears to be random values is because it is actually printing out what's stored in memory at that location, this could be anything from code to actual data.

RANDARRAY function - Office Support, The RANDARRAY function returns an array of random numbers. You can specify the number of rows and columns to fill, minimum and features are rolled out to Microsoft 365 subscribers, see When do I get the newest features for Microsoft 365. If your supporting data is in an Excel table, then the array will automatically  Hello, My program is to generate a two dimensional array of random integers between 0 and 40, each row of this array is X, Y, and Z of a plane.

The code defines your 10x10 array as a 9x9 array. Treating it as a 10x10 array produces a bunch our out-of-bounds accesses. int table[10][10] will work much better. And in general, use manifest constants for sizes:

const int height = 10;
const int width = 10;
int table[height][width];
for (int i = 0; i < height; ++i) ...

Two-Dimensional Arrays \ Processing.org, A matrix can be thought of as a grid of numbers, arranged in rows and columns j < rows; j++) { myArray[i][j] = int(random(255)); } } // Draw points for (int i = 0; i < cols; Color calculated using sine wave fill(127+127*sin(angle)); rect(x,y,w,h); } }​  In a data set starting in Row 4, you may need to add or subtract a numerical value depending on the method you use. If you are going to be coding for a data set that has blank rows or columns within it, always be sure to test out your code to make sure it is calculating properly. Ways To Find The Last Row

The array you are creating is of size 9x9. So while you are printing the 10th row of a 9x9 array it prints the garbage value because 10th row doesn't exist. So in order to create 10x10 array declare it in the following way int array[10][10].

Javanotes 8.1, Section 7.5 -- Two-dimensional Arrays, The elements of a 2D array are arranged in rows and columns, and the new So​, for example, to fill the Life grid with random values, the program uses simple nested But in my program, I actually do something that is common in 2D computer say that the row "above" is actually the bottom row, row number GRID_SIZE-1. So i am able to create a 5x10 2D array with random numbers. however im trying to figure out how to assign each row a giveen value range. such as: Row 1: 0-1 Row 2: 1-0 . . . Row 10: 9-10 Can someone give me a hint on how to acomplish this task.

Please help me with this question Lab – Multidimensional Arrays , Be able to work with individual rows and columns in a two-dimensional array. Introduction Fill the 2-D array with random numbers between 50 and 80. To animate the algorithm, put this method call as the last element in your inner for loop Why do we use two for loops with two-dimensional arrays? One to move over the rows, and one for the columns. Consider the following code that stores values in a 5 x 3 array called grid:

[PDF] Two-Dimensional Arrays, dimensional arrays, a single line of elements. • Often data come naturally in subscripts, one for the row and one for the column. • Example: row col rating[0][2] = 2 rating[1][3] = references fills the array with null values. • Example: GiftCard[][​]  Fill all cells with totally random numbers from 1 to 4. Check if the numbers don't repeat in row or column [edit]If repeating numbers were found, go back to step 1, otherwise print/return result array. Try this and see if it works and how much iteration it needs. You could then optimize this.

Creating an array (1 column 10 rows) of random numbers with no , Hi John,. Try something like this: =arrayformula( array_constrain( unique( randbetween( $C$5, $C$6 * sign(sequence(20)) ) ), 10, 1 ) ). Introduction to C Programming Arrays Overview. An array is a collection of data items, all of the same type, accessed using a common name. A one-dimensional array is like a list; A two dimensional array is like a table; The C language places no limits on the number of dimensions in an array, though specific implementations may.

Comments
  • How many rows are you printing out?
  • you shouldn't iterate over invalid indices. 8 is the last index not 9
  • Your for loops go one index beyond what you have allocated in the table. The <= should only be a <.
  • @FabioTurati You're right, I updated my answer. Thanks!