children

I don't know if there is an issue, but I was wondering why the overflow:hidden does not function on fixed parent/children element. Here's an example: CSS and HTML: .parent{ position:fixed; overflow:hidden; width:300px; height:300px; background:#555; } .children{ position:fixed; top:200px; left:200px; width:150px; height:150px; background:#333; } <div class="parent"> <div class="children"> </div> </div> Live demo: jsFiddle Because a fixed position element is fixed with respect to the viewport, not another element. Therefore since the viewport isn't cutting it off, the overflow becomes

I was wondering, JavaScript offers a variety of methods to get the first child element from any element, but which is the best? By best, I mean: most cross-browser compatible, fastest, most comprehensive and predictable when it comes to behaviour. A list of methods/properties I use as aliases: var elem = document.getElementById('container'); var child = elem.children[0]; var child = elem.firstElementChild; // == children[0] This works for both cases: var child = elem.childNodes[0]; // or childNodes[1], see below That’s in case of forms, or <div> iteration. If I might encounter text elements:

例子： object test extends App { val fruits = Seq( "apple" , "banana" , "orange" ) println(fruits.map(_.toUpperCase)) println(fruits.flatMap(_.toUpperCase)) } 输出: List (APPLE, BANANA, ORANGE) List (A, P, P, L, E , B, A, N , A, N , A, O , R, A, N , G, E ) 例子: object test extends App { def toInt(s: String): Option[Int] = { try { Some(Integer.parseInt(s.trim)) } catch { // catch Exception to catch null 's' case e: Exception => None } } val strings = Seq( "1" , "2" , "foo" , "3" , "bar" ) println(strings.map(toInt)) println(strings.flatMap(toInt)) } 输出: List( Some( 1 ) , Some( 2 ) , None, Some( 3 ) ,