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+5

Multidimensional Arrays

Can someone explain these to me please. int[][] arr = new int[5][10] I understand the above but I dont understand what comes after that. When you iterate through the array to get certain values I get very confused. Please help, thx

3/10/2018 12:07:42 AM

Tim Millar

9 Answers

New Answer

+15

It's just the initialisation of multidimentionnal array. 5 and 10 is the length of array. For now, array are empty.

+12

Yes. For iterate a multi array, need 2 or more for.

+10

int[][] arr = new int[5][10] Creates an array of 5 rows and 10 columns. To search the array for a certain value, you loop over the rows, then the columns: for(int r=0; r<5; r++) { for(int c=0; c<10; c++) { if(arr[r][c] == value) { //do something } //else keep looking } //end of columns } //end of rows You use the same kind of loop to fill the array, print out every value of the array, any sort of processing of data in the array.

+10

Yours is in c++, not java 😏

+6

think of it like arr[rows][columns] 5 rows of 10 values for ( int i = 0; i < 5; i++ ) for ( int j = 0; j < 2; j++ ) { cout << "arr[" << i << "][" << j << "]: "; cout << a[i][j]<< endl; }

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+3

+3

java is similar I guess, was looking for java answer but the loop process is the same just not the cout stuff. iam still confused but thx to all who helped thus far

+1

think of it as a list inside a list. So, int[][]_2D_array = new int[m][n] would mean an (empty) array (_2D_array) of size m*n that will contain two lists/arrays. You'll need 2-loops (for loop is common) to access elements in _2D_array. The first tracks indices of first list ([m]) and the second loop handles that of [n]. You could print a matrix of M x N with this logic