how to merge two sorted array in one sorted array in JavaScript without using sort()

Question

In this program merged two array and then sorted using temp.but this not correct method.because two array are sorted ,so method should be unique i.e. merging of two sorted i

Answer 1

Hey I ran everyone's code from above against a simple .concat() and .sort() method. With both large and small arrays, the .concat() and .sort() completes in less time, significantly.

console.time("mergeArrays");
mergeArrays([1,2,3,5,9],[4,6,7,8])
console.timeEnd("mergeArrays");
//mergeArrays: 0.299ms

console.time("concat sort");
[1,2,3,5,9].concat([4,6,7,8]).sort();
console.timeEnd("concat sort");
//concat sort:0.018ms

With arrays of 10,000 size, the difference is even larger with the concat and sort running even faster than before (4.831 ms vs .008 ms).

What's happening in javascript's sort that makes it faster?