To explore JavaScript beyond what we cover in this tutorial, consider completing theW3School’s free JavaScript training. Basic JavaScript Syntax While human languages rely on grammar to make sense, programming languages rely on syntax. These are the set of rules that define how you need to write...
Use theelse ifstatement to specify a new condition if the first condition is false. Syntax if(condition1) { //block of code to be executed if condition1 is true }elseif(condition2) { //block of code to be executed if the condition1 is false and condition2 is true ...
The variable carName will have the value undefined after the execution of this statement: Example var carName; Re-Declaring JavaScript Variables If you re-declare a JavaScript variable, it will not lose its value. The variable carName will still have the value "Volvo" after the execution of ...
I have written the following information from the w3school documentation: window.onbeforeunload = function () { return "Are you sure?"; } The current approach is effective, but what caused the failure of the previous method? Can we activate a trigger when the user closes their browser or tab?
http://www.w3school.com.cn/htmldom/dom_obj_style.asp http://www.w3school.com.cn/css/css_reference.asp https://developer.mozilla.org/en/Gecko_DOM_Reference https://developer.mozilla.org/en/The_DOM_and_JavaScript https://developer.mozilla.org/en/DOM/document ...