CODEWITHSUNDEEP
javascript
user8022016
user8022016

Reputation:

How to check the sum of every lines in js

Okay, so if I have this:

var array = ["1", "2", "3", "4", "5", "6", "7", "8", "9"];

And what I want is to sum:

1 + 2 + 3 && 1 + 4 + 7 && 1 + 5 + 9

Like in tic tac toe, so my question is how can I do that without filling my code with 300 lines of code?

Upvotes: 1

Views: 77

Answers (2)

kinbiko
kinbiko

Reputation: 2155

Assuming the array is always 9 entries, this is easiest done by identifying the indexes manually. The indexes are 0...8:

0 1 2
3 4 5
6 7 8

We can then model the rows, columns and diagonals as such:

const rows = [
  [0, 1, 2], //Top row
  [3, 4, 5], //Middle row
  [6, 7, 8]  //Bottom row
];

const columns = [
  [0, 3, 6], //Left column
  [1, 4, 7], //Middle column
  [2, 5, 8]  //Right column
];

const bsDiag = [0, 4, 8]; //Backslash diagonal "\"
const fsDiag = [6, 4, 2]; //Forward slash diagonal "/"

Then extract the sums from the array array:

const rowSums = rows.map((row, index) => array[row[0]] + array[row[1]] + array[row[2]]);
const columnSums = columns.map((col, index) => array[col[0]] + array[col[1]] + array[col[2]]);
const bsDiagSum = array[bsDiag[0]] + array[bsDiag[1]] + array[bsDiag[2]]
const fsDiagSum = array[fsDiag[0]] + array[fsDiag[1]] + array[fsDiag[2]]

And now you can print your results with

rowSums.forEach((sum, index) => console.log(`Row ${index + 1} has sum: ${sum}`));
columnSums.forEach((sum, index) => console.log(`Column ${index + 1} has sum: ${sum}`));
console.log(`Backslash diagonal has sum ${bsDiagSum}`);
console.log(`Forward slash diagonal has sum ${fsDiagSum}`);

In your question your array had string values, rather than numbers. This answer assumes the array contains numbers. I'll leave the conversion from strings to numbers as a google exercise.

Upvotes: 1

Nina Scholz
Nina Scholz

Reputation: 386650

You could take two arrays with the start values of row and column and take the sum as index for calculating the wanted sum.

              15
            /
  1   2   3 |  6
  4   5   6 | 15
  7   8   9 | 24
--- --- --- \
 12  15  18   15


var array = ["1", "2", "3", "4", "5", "6", "7", "8", "9"],
    rows = [0, 3, 6].map(i => [0, 1, 2].reduce((s, j) => s + +array[i + j], 0)),
    cols = [0, 1, 2].map(i => [0, 3, 6].reduce((s, j) => s + +array[i + j], 0)),
    slash = [0, 4, 8].reduce((s, i) => s + +array[i], 0),
    backslash = [2, 4, 6].reduce((s, i) => s + +array[i], 0);
    
console.log(rows);       // -
console.log(cols);       // |
console.log(slash);      // /
console.log(backslash);  // \
.as-console-wrapper { max-height: 100% !important; top: 0; }

Upvotes: 1

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