To add a class to an element, without removing/affecting existing values, append a space and the new classname, like so: document.getElementById("MyElement"). ... <看更多>

From: StackOverflow. To change all classes for an element: document.getElementById("MyElement").className = "MyClass";. To add an additional class to an ... ... <看更多>

Check If an Element contains a Class. If this JavaScript tutorial saves you hours of work, please whitelist it in your ad blocker and. ... <看更多>