https://github.com/klemek/betterlists
An extension of java List interface which include some of the C# LINQ useful functions.
https://github.com/klemek/betterlists
java java-8 java-library java8 linq linq-methods maven maven-repository
Last synced: about 2 months ago
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An extension of java List interface which include some of the C# LINQ useful functions.
- Host: GitHub
- URL: https://github.com/klemek/betterlists
- Owner: klemek
- License: apache-2.0
- Archived: true
- Created: 2018-02-21T17:57:16.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2020-10-12T19:09:38.000Z (over 5 years ago)
- Last Synced: 2025-07-31T00:25:24.264Z (7 months ago)
- Topics: java, java-8, java-library, java8, linq, linq-methods, maven, maven-repository
- Language: Java
- Size: 87.9 KB
- Stars: 2
- Watchers: 1
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
Awesome Lists containing this project
README
# BetterLists
[](https://search.maven.org/search?q=g:%22com.github.klemek%22%20AND%20a:%22betterlists%22)
[](https://travis-ci.org/Klemek/BetterLists)
[](https://github.com/boyter/scc/#badges-beta)
[](https://coveralls.io/github/Klemek/BetterLists?branch=master)
[](https://lgtm.com/projects/g/Klemek/BetterLists/context:java)
[](https://lgtm.com/projects/g/Klemek/BetterLists/alerts/)
An extension of the java.util.List interface which include some of the C# LINQ useful functions.
List classes are extended as well. (ArrayList -> BetterArrayList)
Current version v1.4
Before BetterLists :
```Java
ArrayList contacts = someFunction();
ArrayList contactsEmails = new ArrayList<>();
for(int i = 5; i < contacts.size(); i++){
if(c.getEmail() != null){
contactsEmails.add(c.getEmail());
}
}
```
With BetterLists :
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
BetterList contactsEmails = contacts.skip(5)
.where(c -> c.getEmail() != null)
.select(c -> c.getEmail());
```
NOTE : Please note that, unlike C# LINQ, these functions are not optimized at low levels and will have the same impact as standard loops in your program.
## Download
[betterlists-1.4.jar](../../releases/download/betterlists-1.4/betterlists-1.4.jar)
## Maven
You can use this project as a maven dependency with this :
```XML
com.github.klemek
betterlists
1.4
```
## All code examples
### List
| Name | Description |
| :- | :- |
| [all](#all) | Determines whether all elements of the sequence satisfy a condition. |
| [any](#any) | Determines whether any element of the sequence satisfies a condition. |
| [count](#count) | Returns a number that represents how many elements in the specified sequence satisfy a condition. |
| [exclusion](#exclusion) | Produces the set exclusion of two sequences. |
| [first / firstOrDefault](#first-firstordefault) | Returns the first element in the sequence that satisfies a specified condition. (Returns an error if no elements match the condition unless you use the firstOrDefault function) |
| [last / lastOrDefault](#last-lastordefault) | Returns the last element in the sequence that satisfies a specified condition. (Returns an error if no elements match the condition unless you use the lastOrDefault function) |
| [max](#max) | Invokes a transform function on each element of the sequence and returns the maximum nullable Double value. |
| [mean](#mean) | Computes the mean of the sequence of Double values that are obtained by invoking a transform function on each element of the input sequence. |
| [min](#min) | Invokes a transform function on each element of the sequence and returns the minimum nullable Double value. |
| [orderBy / orderByDescending](#orderby-orderbydescending) | Sorts the elements of a sequence in ascending order by using a specified comparator. (You can user orderByDescending to change the order) |
| [reverse](#reverse) | Inverts the order of the elements in the sequence. |
| [select](#select) | Projects each element of a sequence into a new form. |
| [selectMany / selectManyArrays](#selectmany-selectmanyarrays) | Projects each element of a sequence into a new list and flattens the resulting sequences into one sequence. |
| [skip / skipWhile](#skip-skipwhile) | Bypasses elements in the sequence as long as a specified condition is true and then returns the remaining elements. |
| [sum](#sum) | Computes the sum of the sequence of Double values that are obtained by invoking a transform function on each element of the input sequence. |
| [take / takeWhile](#take-takewhile) | Returns a specified number of contiguous elements from the start of the sequence. |
| [union](#union) | Produces the set union of two sequences. |
| [where](#where) | Filters a sequence of values based on a predicate. |
### all
Determines whether all elements of the sequence satisfy a condition.
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
boolean allAdults = contacts.all(c -> c.getAge() >= 21);
```
### any
Determines whether any element of the sequence satisfies a condition.
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
boolean someUnderage = contacts.any(c -> c.getAge() < 21);
```
### count
Returns a number that represents how many elements in the specified sequence satisfy a condition.
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
int adultsCount = contacts.count(c -> c.getAge() >= 21);
```
### exclusion
Produces the set exclusion of two sequences.
```Java
BetterArrayList frenchContacts = BetterArrayList.fromList(someFunction());
ArrayList validContacts = someOtherFunction();
BetterList invalidFrenchContacts = frenchContacts.exclusion(validContacts);
```
### first / firstOrDefault
Returns the first element in the sequence that satisfies a specified condition. (Throws an error if no elements match the condition unless you use the `firstOrDefault` function)
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
Contact firstManager = contacts.first(c -> c.isManager()); //can throw NoSuchElementException
Contact firstContact = contacts.firstOrDefault(null); //return null if the list is empty
```
### last / lastOrDefault
Returns the last element in the sequence that satisfies a specified condition. (Throws an error if no elements match the condition unless you use the `lastOrDefault` function)
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
Contact lastRegular = contacts.last(c -> !c.isManager()); //can throw NoSuchElementException
Contact lastManager = contacts.lastOrDefault(c -> c.isManager(), null); //return null there is no manager
```
### max
Invokes a transform function on each element of the sequence and returns the maximum nullable Double value.
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
int maxAge = (int)contacts.max(c -> (double)c.getAge());
```
### mean
Computes the mean of the sequence of Double values that are obtained by invoking a transform function on each element of the input sequence.
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
int meanAge = (int)contacts.mean(c -> (double)c.getAge());
```
### min
Invokes a transform function on each element of the sequence and returns the minimum nullable Double value.
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
int minAge = (int)contacts.min(c -> (double)c.getAge());
```
### orderBy / orderByDescending
Sorts the elements of a sequence in ascending order by using a specified comparer. (You can user `orderByDescending` to change the order)
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
BetterList orderedContacts = contacts.orderBy(c -> c.getName);
BetterList orderedContacts2 = contacts.orderByDescending(c -> c.getAge()); //oldest first
```
### reverse
Inverts the order of the elements in the sequence.
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
BetterList reversedContacts = contacts.reverse();
```
### select
Projects each element of a sequence into a new form.
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
BetterList contactsMails = contacts.select(c -> c.getEmail());
```
### selectMany / selectManyArrays
Projects each element of a sequence into a new list and flattens the resulting sequences into one sequence.
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
BetterList contactsNumbers = contacts.selectMany(c -> c.getAllPhoneNumbers());
BetterList contactsMails = contacts.selectManyArrays(c -> c.getEmail().split(";"));
```
### skip / skipWhile
Bypasses elements in the sequence as long as a specified condition is true and then returns the remaining elements.
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
BetterList contacts2 = contacts.skip(3);
BetterList contacts3 = contacts.skipWhile(c -> c.getEmail().startsWith("society"));
```
### sum
Computes the sum of the sequence of Double values that are obtained by invoking a transform function on each element of the input sequence.
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
double salary = contacts.skip(c -> c.getSalary());
```
### take / takeWhile
Returns a specified number of contiguous elements from the start of the sequence.
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
BetterList contacts2 = contacts.take(5);
BetterList contacts3 = contacts.takeWhile(c -> c.getEmail().startsWith("society"));
```
### union
Produces the set union of two sequences.
```Java
BetterArrayList frenchContacts = BetterArrayList.fromList(someFunction());
ArrayList validContacts = someOtherFunction();
BetterList validFrenchContacts = frenchContacts.union(validContacts);
```
### where
Filters a sequence of values based on a predicate.
```Java
BetterArrayList contacts = BetterArrayList.fromList(someFunction());
BetterList validContacts = contacts.where(c -> c.getEmail() != null);
```