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C#/Linq: Apply a mapping function to each element in an IEnumerable?
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You can just use the Select() extension method:
IEnumerable<int> integers = new List<int>() { 1, 2, 3, 4, 5 };
IEnumerable<string> strings = integers.Select(i => i.ToString());
Or in LINQ syntax:
IEnumerable<int> in...
Swift Beta performance: sorting arrays
...he left partition always first.) Quicksort implemented with a simple pivot selection in the worst case takes O(n^2) time, but even in this worst case you only need O(log n) stack space by recursing on the smaller partition first.
– Macneil Shonle
Mar 16 '15 at ...
MySQL show current connection info
...e are MYSQL functions you can use. Like this one that resolves the user:
SELECT USER();
This will return something like root@localhost so you get the host and the user.
To get the current database run this statement:
SELECT DATABASE();
Other useful functions can be found here: http://dev.mys...
Find an element in DOM based on an attribute value
...ears the landscape has changed drastically. You can now reliably use querySelector and querySelectorAll, see Wojtek's answer for how to do this.
There's no need for a jQuery dependency now. If you're using jQuery, great...if you're not, you need not rely it on just for selecting elements by att...
Get element inside element by class and ID - JavaScript
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Well, first you need to select the elements with a function like getElementById.
var targetDiv = document.getElementById("foo").getElementsByClassName("bar")[0];
getElementById only returns one node, but getElementsByClassName returns a node list...
How do I use LINQ Contains(string[]) instead of Contains(string)
...re that the query can be used with more providers.
var uids = arrayofuids.Select(id => int.Parse(id)).ToList();
var selected = table.Where(t => uids.Contains(t.uid));
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How to set data attributes in HTML elements
...e.
$("#button").on("click", function() {
var field = document.querySelector("#textfield")
switch ($("#method").val()) {
case "setAttribute":
field.setAttribute("data-customval", field.value)
break;
case "dataset":
field.dataset.customval = field.value
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MySQL indexes - what are the best practices?
...t them. Generally I put an index on any fields that I will be searching or selecting using a WHERE clause but sometimes it doesn't seem so black and white.
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Random row selection in Pandas dataframe
Is there a way to select random rows from a DataFrame in Pandas.
6 Answers
6
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SQL standard to escape column names?
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For MySQL, use back ticks `.
For instance:
SELECT `column`, `column2` FROM `table`
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