You can use the qualities of the abstract equality operator to do this: if (variable == null){ // your code here. } Because null == undefined is true, ... ... <看更多>

How to check if result is not ' Null ', ' Undefined ' or 'Empty' in JavaScript while using conditions? Lets discuss ' if not undefined, null or ... ... <看更多>

workOrderId"); if(woId != undefined && woId != null && woId != ''){ component.set("v.showSpinner",true); //component.set("v. ... <看更多>

ForbesLindesay commented on Dec 9, 2012 ... The same is actually true of undefined variables in regular JavaScript. 17 ... <看更多>

view raw 使用typeof檢驗undefined和null.js hosted with ❤ by GitHub ... 有時候我們在寫if else等判斷式，寫的會像上面的程式碼一樣。 ... <看更多>