How to change css property using javascript

I want to change css property of class using javascript. What i actually want is when a div is hoverd, another div should become visible. My css is like.. And html file is like.. When hello1 div is hovered, bye1 div should be visible and similarly bye2 should appear when hello2 is hovered. http://jsfiddle.net/rohan23dec/TqDe9/1/

Merge/flatten an array of arrays

You can use concat to merge arrays:  Run code snippetExpand snippet Using the apply method of concat will just take the second parameter as an array, so the last line is identical to this: There is also the Array.prototype.flat() method (introduced in ES2019) which you could use to flatten the arrays, although it is only available in Node.js starting with version 11, and not … Read more

What’s the difference between console.dir and console.log?

In Firefox, these function behave quite differently: log only prints out a toString representation, whereas dir prints out a navigable tree. In Chrome, log already prints out a tree — most of the time. However, Chrome’s log still stringifies certain classes of objects, even if they have properties. Perhaps the clearest example of a difference is a regular expression: You can also see a clear difference … Read more

What is the difference between call and apply?

The difference is that apply lets you invoke the function with arguments as an array; call requires the parameters be listed explicitly. A useful mnemonic is “A for array and C for comma.” See MDN’s documentation on apply and call. Pseudo syntax: theFunction.apply(valueForThis, arrayOfArgs) theFunction.call(valueForThis, arg1, arg2, …) There is also, as of ES6, the possibility to spread the array for use with the call function, you can see the compatibilities here. Sample code:

jQuery animate backgroundColor

The color plugin is only 4kb so much cheaper than the UI library. Of course you’ll want to use a decent version of the plugin and not some buggy old thing which doesn’t handle Safari and crashes when the transitions are too fast. Since a minified version isn’t supplied you might like test various compressors and make your own min version. … Read more