Question

How to use Array.reduce() to flatten an array of arrays in JavaScript

Answer 1

var arr = [[0, 1], [2, 3], [4, 5], [6, 7]]

var arr_flat = arr.reduce(function(a, b) {
  return a.concat(b);
}, []);

console.log(arr_flat); 
 
 
/*
run:  
  
[0, 1, 2, 3, 4, 5, 6, 7]
   
*/

 

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