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Samples of Scala and Java code where Scala code looks simpler/has fewer lines?
...cker's example and use Scala's case classes:
case class Person(firstName: String, lastName: String)
The above Scala class contains all features of the below Java class, and some more - for example it supports pattern matching (which Java doesn't have). Scala 2.8 adds named and default arguments, ...
Split a collection into `n` parts with LINQ?
...OfChunks");
int sizePerPacket = items.Count / numberOfChunks;
int extra = items.Count % numberOfChunks;
for (int i = 0; i < numberOfChunks - extra; i++)
yield return items.Skip(i * sizePerPacket).Take(sizePerPacket);
int alreadyReturnedCount = (numberOfChunks - extra) *...
Ensuring json keys are lowercase in .NET
...wercaseContractResolver : DefaultContractResolver
{
protected override string ResolvePropertyName(string propertyName)
{
return propertyName.ToLower();
}
}
Usage:
var settings = new JsonSerializerSettings();
settings.ContractResolver = new LowercaseContractResolver();
var json...
What is the difference between ? and Object in Java generics?
...
An instance of HashMap<String, String> matches Map<String, ?> but not Map<String, Object>. Say you want to write a method that accepts maps from Strings to anything: If you would write
public void foobar(Map<String, Object> ms...
Postgresql SELECT if string contains
...
A proper way to search for a substring is to use position function instead of like expression, which requires escaping %, _ and an escape character (\ by default):
SELECT id FROM TAG_TABLE WHERE position(tag_name in 'aaaaaaaaaaa')>0;
...
How to do a LIKE query in Arel and Rails?
...ers[:name].matches("%#{user_name}%"))
PS:
users = User.arel_table
query_string = "%#{params[query]}%"
param_matches_string = ->(param){
users[param].matches(query_string)
}
User.where(param_matches_string.(:name)\
.or(param_matches_string.(:description)))
...
Can we write our own iterator in Java?
...ntIndex. Below is an example of using this API...
public static void main(String[] args) {
// create an array of type Integer
Integer[] numbers = new Integer[]{1, 2, 3, 4, 5};
// create your list and hold the values.
SOList<Integer> stackOverflowList = new SOList<Integer&g...
RandomForestClassifier vs ExtraTreesClassifier in scikit learn
Can anyone explain the difference between the RandomForestClassifier and ExtraTreesClassifier in scikit learn. I've spent a good bit of time reading the paper:
...
Accessing the index in 'for' loops?
... @user12379095 you probably have the data in the wrong type (a string) and you need to convert it to an actual list of numbers instead of a string. That is somewhat off topic here, please delete your comment and flag mine to be deleted as no longer needed when you see this.
...
Where is array's length property defined?
...ytecode instruction: arraylength. So this method:
public static void main(String[] args) {
int x = args.length;
}
is compiled into bytecode like this:
public static void main(java.lang.String[]);
Code:
0: aload_0
1: arraylength
2: istore_1
3: return
So it's not access...