Pvag
/ matrixToArray.js
Last active
February 7, 2019 23:09
An example on how to sum elements by column in a 2D matrix. An exercise, using array iterators (i.e. reduce and map).
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| const nums = [1, 10, 100]; | |
| const matrix = [nums, nums, nums]; // each nums array represents a row in matrix | |
| // reduce accumulates, for each row, the sum of elements in the same column | |
| const columnsSum = matrix.reduce( (accumulated, actual) => { | |
| // this sums element by element, the accumulated array and the actual row | |
| return accumulated.map( (n, index) => { | |
| return n + actual[index]; | |
| }); | |
| }); | |
| console.log(colSums); // prints [3, 30, 300] |