use concat arrays for multiple array in node js code example
Example 1: merge array in js
//for ES5
var array1 = ["Rahul", "Sachin"];
var array2 = ["Sehwag", "Kohli"];
var output = array1.concat(array2);
console.log(output);
//for ES6, we use spread operators to concat arrays
var array1 = ["Dravid", "Tendulkar"];
var array2 = ["Virendra", "Virat"];
var output = [...array1, ...array2];
console.log(output);
Example 2: js join two arrays
[1,2,3].concat([4,5,6])
// [1,2,3,4,5,6]