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Key existence check in HashMap
...
Do you ever store a null value? If not, you can just do:
Foo value = map.get(key);
if (value != null) {
...
} else {
// No such key
}
Otherwise, you could just check for existence if you get a null value returned:
Foo value = map.get(key);
if (v...
Using a bitmask in C#
....None;
Logical bitwise combinations can be tough to remember, so I make life easier on myself with a FlagsHelper class*:
// The casts to object in the below code are an unfortunate necessity due to
// C#'s restriction against a where T : Enum constraint. (There are ways around
// this, but they'r...
How do I detect if I am in release or debug mode?
... is a boolean value that will be true for a debug build, false otherwise:
if (BuildConfig.DEBUG) {
// do something for a debug build
}
There have been reports that this value is not 100% reliable from Eclipse-based builds, though I personally have not encountered a problem, so I cannot say how ...
Comparing date ranges
In MySQL, If I have a list of date ranges (range-start and range-end). e.g.
10 Answers
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Java: splitting a comma-separated string but ignoring commas in quotes
...blurb"
> d;junk="quux,syzygy"
In other words: split on the comma only if that comma has zero, or an even number of quotes ahead of it.
Or, a bit friendlier for the eyes:
public class Main {
public static void main(String[] args) {
String line = "foo,bar,c;qual=\"baz,blurb\",d;jun...
How to determine if a decimal/double is an integer?
How do I tell if a decimal or double value is an integer?
14 Answers
14
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How do you pass multiple enum values in C#?
... isTuesdaySet = (days & DaysOfWeek.Tuesday) == DaysOfWeek.Tuesday;
if (isTuesdaySet)
//...
// Do your work here..
}
public void CallMethodWithTuesdayAndThursday()
{
this.RunOnDays(DaysOfWeek.Tuesday | DaysOfWeek.Thursday);
}
For more details, see MSDN's documentation on Enume...
MySQL - why not index every field?
...f thumb probably. But otherwise you could do a lot of reading it turns out if you want to become expert on indices. eg. stackoverflow.com/questions/3049283/…
– Andrew
Jan 11 '19 at 18:28
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How do I find the current executable filename? [duplicate]
... This one tends to add ".vhost." in the filename, an issue not present if using System.Reflection.Assembly.GetEntryAssembly().Location (see alternate answer).
– Contango
Aug 2 '12 at 15:59
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How do I convert a TimeSpan to a formatted string? [duplicate]
I have two DateTime vars, beginTime and endTime. I have gotten the difference of them by doing the following:
14 Answers
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