JSFiddle - React, Tailwind, and code Playground

JavaScript

var Chem1 = "water"
var CAS1 = "00566"
var MW1 = "666"

var csv_content = []
var csv_content_final = []
csv_content[0] = ["Chemical, CAS, MW"];
var chem_property = [Chem1, CAS1, MW1];
csv_content[1] = chem_property;
for (kkk = 0; kkk < csv_content.length; kkk++) {
      console.log(csv_content[kkk]);
      csv_content_final[kkk] = csv_content[kkk] + '\n';
      console.log(csv_content_final[kkk]);
}
console.log(csv_content_final);
alert(csv_content_final);