Javascript is very flexible with regards to checking for "null" values. I'm guessing you're actually looking for empty strings, in which case this simpler ... ... <看更多>

JavaScript null is a primitive type that contains a special value null . JavaScript uses the null value to represent the intentional absence of any object ... ... <看更多>

JavaScript null 、undefined 與undeclared · 宣告了，但是還沒有賦值. var a = undefined; console. · 物件沒有該屬性. var person = { name: "elaine", }; ... ... <看更多>

However, recently, I've found myself getting deeper into the JavaScript language. Recently, I've heard about "truthy" and falsey values. However, I don't fully ... ... <看更多>