< input type = "number" id = "myinput" > //因為input取的值是字串(string) 所以取值要轉成數字(number) //所以即使input 的type設定為number 但typeof去檢測都是string 所有原文 <! DOCTYPE html > < html lang = "en" > < head > < meta charset = "UTF-8" > < meta name = "viewport" content = "width=device-width, initial-scale=1.0" > < meta http-equiv = "X-UA-Compatible" content = "ie=edge" > < title > Document </ title > </ head > < body > < input type = "number" id = "myinput" > < button onclick = " func ()" > go </ button > < br > < div id = "output" ></ div > < script > let myinput = document . querySelector ( '#myinput' ); let output = document . querySelector ( '#output...