Is 2d array a double pointer? No. This line of your program is incorrect: int **ptr = (int**)matrix; This answer deals with the same topic If you want concrete image how multidimensional arrays are implemented: The rules for multidimensional arrays are not different from those for ordinary arrays, just substitute the “inner” array type as … Read more
When it comes to describing parameters, arrays always decay into pointers to their first element. When you pass an array declared as int Array[3] to the function void foo(int array[]), it decays into a pointer to the beginning of the array i.e. int *Array;. Btw, you can describe a parameter as int array[3] or int … Read more
According the NumPy tutorial, the correct way to do it is: a[tuple(b)]
First, you must allocate and initialize your objects before use, something like: NSMutableArray * sections = [[NSMutableArray alloc] initWithCapacity:10]; For the rows, you need one object for each, not a single NSMutableArray * rows; Second, depending on whether you’re using Xcode 4.4+ (which introduced subscripting, a.k.a section[i] & section[i] = …) you may have to … Read more
How about: $arr = Array ( 0 => Array ( ‘name’ => ‘Jonah’, ‘age’ => ’27’, ), 1 => Array ( ‘name’ => ‘Bianca’, ‘age’ => ’32’, ), 2 => Array ( ‘name’ => ‘Jonah’, ‘age’ => ’25’, ), 3 => Array ( ‘name’ => ‘Bianca’, ‘age’ => ’35’, ), ); function comp($a, $b) { … Read more
You can use usort as: function cmp($a, $b) { return $a[‘weight’] – $b[‘weight’]; } usort($arr,”cmp”);
What you are doing is printing the value in the array at spot [3][3], which is invalid for a 3by3 array, you need to loop over all the spots and print them. for(int i = 0; i < 3; i++) { for(int j = 0; j < 3; j++) { printf(“%d “, array[i][j]); } printf(“\n”); … Read more
In response your comment question, let’s compare 2 ways of creating an array First make an array from a list of arrays (all same length): In [302]: arr = np.array([np.arange(3), np.arange(1,4), np.arange(10,13)]) In [303]: arr Out[303]: array([[ 0, 1, 2], [ 1, 2, 3], [10, 11, 12]]) The result is a 2d array of numbers. … Read more
You can initialize arrays in both ways, though the usage of curly inner braces is recommended as it improves the readability. The easiest way to find the value of an element of a multi-dimensional array non-formatted with braces is by splitting the array. For example, your array’s dimensions are 2x3x2: First split the array into … Read more
It’s easier to understand what np.vstack, np.hstack and np.dstack* do by looking at the .shape attribute of the output array. Using your two example arrays: print(a.shape, b.shape) # (3, 2) (3, 2) np.vstack concatenates along the first dimension… print(np.vstack((a, b)).shape) # (6, 2) np.hstack concatenates along the second dimension… print(np.hstack((a, b)).shape) # (3, 4) and … Read more