Push is not working in node js - json

Question

Here is the code
loginController.prototype.newUserValidation = function(name,email,username,password, callback){
var errorMessage = {};
var name = validator.trim(name);
var email =validator.trim(email);
var username = validator.trim(username);
var password = validator.trim(password);
if(!validator.isLength(name,1)){
errorMessage.push("Name is required field");
}
if(!validator.isLength(email,1)){
errorMessage.push("Email is required field");
} else if(!validator.isEmail(email)){
errorMessage.push("Email is not valid");
}
if(!validator.isLength(username,1)){
errorMessage.push("username is required field");
}
if(!validator.isLength(password,1)){
errorMessage.push("password is required field");
}
callback(errorMessage);
}
This error is coming :
Object # has no method 'push'
TypeError: Object #<Object> has no method 'push'
at Database.loginController.newUserValidation (/home/vinove/Desktop/AshutoshJha/controller/login-controller.js:49:16)
at module.exports (/home/vinove/Desktop/AshutoshJha/routes/index.js:166:14)
at Layer.handle [as handle_request] (/home/vinove/Desktop/AshutoshJha/node_modules/express/lib/router/layer.js:95:5)
at next (/home/vinove/Desktop/AshutoshJha/node_modules/express/lib/router/route.js:131:13)
at Route.dispatch (/home/vinove/Desktop/AshutoshJha/node_modules/express/lib/router/route.js:112:3)
at Layer.handle [as handle_request] (/home/vinove/Desktop/AshutoshJha/node_modules/express/lib/router/layer.js:95:5)
at /home/vinove/Desktop/AshutoshJha/node_modules/express/lib/router/index.js:277:22
at Function.process_params (/home/vinove/Desktop/AshutoshJha/node_modules/express/lib/router/index.js:330:12)
at next (/home/vinove/Desktop/AshutoshJha/node_modules/express/lib/router/index.js:271:10)
at Function.handle (/home/vinove/Desktop/AshutoshJha/node_modules/express/lib/router/index.js:176:3)

Answer 1

This is an object:
var errorMessage = {};
An object is a set of key/value pairs:
{
"name": "john",
"age" : 21
}
If you want to be able to add random data to your variable, you need an array:
var errorMessage = [];
Then your code would work

Answer 2

the push method is available for array datatype.
In your code you are defining json
i.e var errorMessage={}.
internally it is json.
Thats why it showing error Object # has no method 'push'
so too get rid of this error just change
var errorMessage = {};
to
var errorMessage = [];