Javascript

Question

I don't understand different between call case 1 and case 2 , pro can help me ! Thank you so much.

var higher = looger => messsage => { looger(messsage.toUpperCase() + "!!!!") }

var messages = message => console.log(message)

// case 1
var mess = higher( messages )

mess("hao") // HAO!!!

// case 2

higher(messages("hao")) // hao not print Hao!!!

Answer 1

not print nothing because (in 2 case) higher not was called ,but if you call higher will be generate a error that not is applicable the toUpperCase method to an undefined value ,this because you call the messages that not return any string she only print your message.