Res.send and res.json in Express.js

Both methods res.send and res.json are identical when an array or object is passed. Res.json will convert non-objects such as null and undefined. You can format json with more options. This options can be set as:

app.set('json
spaces', 2);
app.set('json
replacer', replacer);

Then passed to JSON.stringify() like:

JSON.stringify(value,

replacer, spacing);
// value: object to
format
// replacer: rules
for transforming properties encountered during stringifying
// spacing: the
number of spaces for indentation

The given below code in res.json() method is not in res.send method.

var app = this.app;
var replacer =
app.get('json replacer');
var spaces =
app.get('json spaces');
var body =
JSON.stringify(obj, replacer, spaces);

It eventually calls res.send()

this.charset =
this.charset || 'utf-8';
this.get('Content-Type')
|| this.set('Content-Type', 'application/json');



return this.send(body);