Question

How to get the first column from a matrix (2D array) in JavaScript

Answer 1

const arr = [
  [1, 2, 3, 5, 9],
  [4, 5, 6, 5, 8],
  [7, 8, 9, 5, 7]
];
   
const firstcol = arr.map(function(value,index) { return value[0]; });
   
console.log(firstcol); 
   
   
     
       
       
/*
run:
       
[1, 4, 7]
       
*/

 

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