In this tutorial, I will explain how recursion works in solving multidimensional array.
lets pretend that we want to find the sum of this array:
[ 3 , 5 , [6] , 7 ,[ 10 ,[ 9 , 1] ] ]
- create a variable sum and make it equal to 0, so we will have a space to save the total.
- in the for-loop, we checking the variable at the index if it is an Array, if not, we sum up the num
when index = 0 , sum += 3 , sum = 3
when index = 1 , sum += 5 , sum = 8 - when index =2, its an array, we start a new function
sum inside the new function starts with 0,
index =0, sum+= 6, sum = 6
end of 1 digit for-loop
now we return this sum = 6
end of 1st recursion - we come out from the recursion,
grabbing the 6 return from the function
and add the sum we got from index 1
so the sum will now be 14 - when index =3, sum +=7, sum =21
- when index =4, its an array, recursion 1
at index = 0 , sum += 10, sum =10 - at index = 1 , recursion 2
at index = 0, sum +=9, sum =9
at index = 1, sum+=1, sum=10
end of array, return sum =10 - grabbing the 10 return from recursion 2
and add the sum we got from index 4, which is 10
so the sum will now be 20
end of array, return 20 - add sum we got before going to the recursion, which is 21, with
the sum return from the recursion, which is 20 - we got the final sum =41