Array Join vs String Concat

Question

Which method is faster?

Array Join:

var str_to_split = \"a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z\";
var myarray = str_to         


        

Answer 1

According to this Google document titled 'Optimizing JavaScript code' string concat is slower then array join but apparently this is not true for modern Javascript engines.

I made a benchmark for the Fibonacci test example that they used in the document and it shows that concatenating (gluing) the string is almost 4x as fast as using Array join.