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How to map and remove nil values in Ruby
...
Ruby 2.7+
There is now!
Ruby 2.7 is introducing filter_map for this exact purpose. It's idiomatic and performant, and I'd expect it to become the norm very soon.
For example:
numbers = [1, 2, 5, 8, 10, 13]
enum.filter_map { |i| i * 2 if i.even? }
# => [4, 16, 20]
In your ...
There is no ViewData item of type 'IEnumerable' that has the key 'xxx'
...ntains a SelectList with the same name as your DropDownList i.e. "submarket_0", the Html helper will automatically populate your DropDownList with that data if you don't specify the 2nd parameter which in this case is the source SelectList.
What happened with my error was:
Because the table contai...
Java 8: performance of Streams vs Collections
...fects on your results. So, I increased your task 10 times
int max = 10_000_000;
and ran your benchmark. My results:
Collections: Elapsed time: 8592999350 ns (8.592999 seconds)
Streams: Elapsed time: 2068208058 ns (2.068208 seconds)
Parallel streams: Elapsed time: 7186967071 ns (7...
Java: PrintStream to String?
...= new ByteArrayOutputStream();
final String utf8 = StandardCharsets.UTF_8.name();
try (PrintStream ps = new PrintStream(baos, true, utf8)) {
yourFunction(object, ps);
}
String data = baos.toString(utf8);
...
What is the performance cost of having a virtual method in a C++ class?
... be non-virtual is an abominable policy.
– underscore_d
May 20 '17 at 19:34
add a comment
...
Build tree array from flat array in javascript
...ibrary. It's, as far as I can tell, the fastest solution.
function list_to_tree(list) {
var map = {}, node, roots = [], i;
for (i = 0; i < list.length; i += 1) {
map[list[i].id] = i; // initialize the map
list[i].children = []; // initialize the children
}
for (i = 0; i ...
Unexpected results when working with very big integers on interpreted languages
...ger types. All numbers are floating points.
– toasted_flakes
Aug 4 '13 at 22:27
8
@grasGendarme T...
How do I set the figure title and axes labels font size in Matplotlib?
... @AlexanderMcFarlane. I ran python -c 'import matplotlib as mpl; print(mpl.__version__); print("figure.titlesize" in mpl.rcParams.keys())'. Result is 1.5.1, True. 1) What version of matplotlib are you using? What version of Python? 2) Could it be a bug where for some reason it accepts str but not un...
in_array() and multidimensional array
I use in_array() to check whether a value exists in an array like below,
22 Answers
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两种js滑动门(tab切换)效果 - 源码下载 - 清泛网 - 专注C/C++及内核技术
...
thisObj.className = "active";
document.getElementById(tabObj+"_Content"+i).style.display = "block";
}else{
tabList[i].className = "normal";
document.getElementById(tabObj+"_Content"+i).style.display = "none";
}
}
}
</script>
</head>
<body>
<div align...