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How to extract numbers from a string and get an array of ints?
I have a String variable (basically an English sentence with an unspecified number of numbers) and I'd like to extract all the numbers into an array of integers. I was wondering whether there was a quick solution with regular expressions?
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How to get names of enum entries?
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enum Enum {
A
}
let nameOfA = Enum[Enum.A]; // "A"
Keep in mind that string enum members do not get a reverse mapping generated at all.
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Java ArrayList copy
... create a new ArrayList based on the other ArrayList you do this:
List<String> l1 = new ArrayList<String>();
l1.add("Hello");
l1.add("World");
List<String> l2 = new ArrayList<String>(l1); //A new arrayList.
l2.add("Everybody");
The result will be l1 will still have 2 eleme...
What is Double Brace initialization in Java?
... has something like map literals, similar to the existing array literals:
String[] array = { "John", "Doe" };
Map map = new HashMap() {{ put("John", "Doe"); }};
Some people may find this syntactically stimulating.
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What is the most frequent concurrency issue you've encountered in Java? [closed]
...erent open source libraries did something like this:
private static final String LOCK = "LOCK"; // use matching strings
// in two different libraries
public doSomestuff() {
synchronized(LOCK) {
this.work();
}
}
At first glance, this look...
differentiate null=True, blank=True in django
...ngo are never saved as NULL. Blank values are stored in the DB as an empty string ('').
A few examples:
models.DateTimeField(blank=True) # raises IntegrityError if blank
models.DateTimeField(null=True) # NULL allowed, but must be filled out in a form
Obviously, Those two options don't make logi...
Java generics type erasure: when and what happens?
... into compile-time checks and execution-time casts. So this code:
List<String> list = new ArrayList<String>();
list.add("Hi");
String x = list.get(0);
is compiled into
List list = new ArrayList();
list.add("Hi");
String x = (String) list.get(0);
At execution time there's no way of ...
Can you attach Amazon EBS to multiple instances?
... to get an EBS volume attached to more than one instance, it would be a _REALLY_BAD_IDEA_. To quote Kekoa, "this is like using a hard drive in two computers at once"
Why is this a bad idea? ...
The reason you can't attach a volume to more than one instance is that EBS provides a "block storage" a...
How do I install cURL on cygwin?
I tried to enable curl on cygwin but it says bash: curl: command not found
17 Answers
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How to check if a String contains only ASCII?
...ue if the character is a letter. But is there a way to quickly find if a String only contains the base characters of ASCII?
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