Difference between res.setHeader and res.header in node.js

Question

What is the difference between res.setHeader and res.header. Which one should be used for enabling CORS? In some pages res.header is used and some pages res.setHeader is use

Answer 1

app.use((req, res, next) => {
  res.setHeader("Access-Control-Allow-Origin", "*");
  res.setHeader(
    "Access-Control-Allow-Headers",
    "Origin, X-Requested-With, Content-Type, Accept"
  );
  res.setHeader(
    "Access-Control-Allow-Methods",
    "GET, POST, PATCH, DELETE, OPTIONS"
  );
  next();
});

I use this code for my mean stack projects.