CU (Nerd4j Utils 2.0.0 API)

java.lang.Object
- org.nerd4j.utils.math.CU

Direct Known Subclasses:

BD, BI
```
public class CU
extends Object
```
This utility class provides some convenience methods do deal with existing legacy classes that implement Comparable.
The name of this class is an abbreviation of Comparable Utilities. We have intentionally used a short name for readability because this class is intended to be used in comparison statements so that you can write something like
```
 if( CU.lt(a,b) )
   // Do something...
 
```
instead of
```
 if( a.compareTo(b) < 0 )
   // Do something...
 
```
If you are dealing with existing comparable classes like String or Integer this class will facilitate the writing of comparison statements.
If you are writing a new comparable class we suggest to implement Comparative instead. This will allow you to implement Comparable and to have the convenience methods provided by this class directly on your comparable object.
Since:

2.0.0

Author:

Massimo Coluzzi

See Also:

Comparative

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static <C extends Comparable<C>> boolean`	`eq(C a, C b)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, tells if `a == b`.
`static <C extends Comparable<C>> boolean`	`eq(C a, C b, boolean nullLast)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, tells if `a == b`.
`static <C extends Comparable<C>> boolean`	`ge(C a, C b)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, tells if `a >= b`.
`static <C extends Comparable<C>> boolean`	`ge(C a, C b, boolean nullLast)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, tells if `a >= b`.
`static <C extends Comparable<C>> boolean`	`gt(C a, C b)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, tells if `a > b`.
`static <C extends Comparable<C>> boolean`	`gt(C a, C b, boolean nullLast)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, tells if `a > b`.
`static <C extends Comparable<C>> boolean`	`le(C a, C b)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, tells if `a <= b`.
`static <C extends Comparable<C>> boolean`	`le(C a, C b, boolean nullLast)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, tells if `a <= b`.
`static <C extends Comparable<C>> boolean`	`lt(C a, C b)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, tells if `a < b`.
`static <C extends Comparable<C>> boolean`	`lt(C a, C b, boolean nullLast)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, tells if `a < b`.
`static <C extends Comparable<C>> C`	`max(C a, C b)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, returns the maximum value between them.
`static <C extends Comparable<C>> C`	`max(C a, C b, boolean nullLast)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, returns the maximum value between them.
`static <C extends Comparable<C>> C`	`min(C a, C b)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, returns the minimum value between them.
`static <C extends Comparable<C>> C`	`min(C a, C b, boolean nullLast)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, returns the minimum value between them.
`static <C extends Comparable<C>> boolean`	`ne(C a, C b)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, tells if {@code a !
`static <C extends Comparable<C>> boolean`	`ne(C a, C b, boolean nullLast)` This is a `null-safe` method that, given two `comparable` values `a` and `b`, tells if {@code a !
`static <T> Comparator<T>`	`nullFirstNaturalOrderComparator()` Returns a `null-safe` natural ordered comparator considering `null` to be less than `non-null`.
`static <T> Comparator<T>`	`nullLastNaturalOrderComparator()` Returns a `null-safe` natural ordered comparator considering `null` to be greater than `non-null`.
`static <T> Comparator<T>`	`nullSafeNaturalOrderComparator(boolean nullLast)` Returns a `null-safe` natural ordered comparator considering `null` to be less than or greater than `non-null` based on the value of the parameter.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - nullFirstNaturalOrderComparator
```
public static <T> Comparator<T> nullFirstNaturalOrderComparator()
```
    Returns a null-safe natural ordered comparator considering null to be less than non-null.
    
    Type Parameters:
    
    T - type of object to compare.
    
    Returns:
    
    a null-safe natural ordered comparator.
  - nullLastNaturalOrderComparator
```
public static <T> Comparator<T> nullLastNaturalOrderComparator()
```
    Returns a null-safe natural ordered comparator considering null to be greater than non-null.
    
    Type Parameters:
    
    T - type of object to compare.
    
    Returns:
    
    a null-safe natural ordered comparator.
  - nullSafeNaturalOrderComparator
```
public static <T> Comparator<T> nullSafeNaturalOrderComparator(boolean nullLast)
```
    Returns a null-safe natural ordered comparator considering null to be less than or greater than non-null based on the value of the parameter.
    
    Type Parameters:
    
    T - type of object to compare.
    
    Parameters:
    
    nullLast - tells to consider null to be greater than non-null.
    
    Returns:
    
    a null-safe natural ordered comparator.
  - lt
```
public static <C extends Comparable<C>> boolean lt(C a,
                                                   C b)
```
    This is a null-safe method that, given two comparable values a and b, tells if a < b.
    This method considers null to be less than non-null.
    This method is the same as CU.lt(a,b,false).
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    Returns:
    
    true if a < b.
  - lt
```
public static <C extends Comparable<C>> boolean lt(C a,
                                                   C b,
                                                   boolean nullLast)
```
    This is a null-safe method that, given two comparable values a and b, tells if a < b.
    This method considers null to be less than or greater than non-null based on the value of nullLast.
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    nullLast - tells if null is greater than non-null.
    
    Returns:
    
    true if a < b.
  - le
```
public static <C extends Comparable<C>> boolean le(C a,
                                                   C b)
```
    This is a null-safe method that, given two comparable values a and b, tells if a <= b.
    This method considers null to be less than non-null.
    This method is the same as CU.le(a,b,false).
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    Returns:
    
    true if a <= b.
  - le
```
public static <C extends Comparable<C>> boolean le(C a,
                                                   C b,
                                                   boolean nullLast)
```
    This is a null-safe method that, given two comparable values a and b, tells if a <= b.
    This method considers null to be less than or greater than non-null based on the value of nullLast.
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    nullLast - tells if null is greater than non-null.
    
    Returns:
    
    true if a <= b.
  - eq
```
public static <C extends Comparable<C>> boolean eq(C a,
                                                   C b)
```
    This is a null-safe method that, given two comparable values a and b, tells if a == b.
    This method considers null to be less than non-null.
    This method is the same as CU.eq(a,b,false).
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    Returns:
    
    true if a == b.
  - eq
```
public static <C extends Comparable<C>> boolean eq(C a,
                                                   C b,
                                                   boolean nullLast)
```
    This is a null-safe method that, given two comparable values a and b, tells if a == b.
    This method considers null to be less than or greater than non-null based on the value of nullLast.
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    nullLast - tells if null is greater than non-null.
    
    Returns:
    
    true if a == b.
  - ne
```
public static <C extends Comparable<C>> boolean ne(C a,
                                                   C b)
```
    This is a null-safe method that, given two comparable values a and b, tells if a != b.
    This method considers null to be less than non-null.
    This method is the same as CU.ne(a,b,false).
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    Returns:
    
    true if a != b.
  - ne
```
public static <C extends Comparable<C>> boolean ne(C a,
                                                   C b,
                                                   boolean nullLast)
```
    This is a null-safe method that, given two comparable values a and b, tells if a != b.
    This method considers null to be less than or greater than non-null based on the value of nullLast.
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    nullLast - tells if null is greater than non-null.
    
    Returns:
    
    true if a != b.
  - ge
```
public static <C extends Comparable<C>> boolean ge(C a,
                                                   C b)
```
    This is a null-safe method that, given two comparable values a and b, tells if a >= b.
    This method considers null to be less than non-null.
    This method is the same as CU.ge(a,b,false).
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    Returns:
    
    true if a >= b.
  - ge
```
public static <C extends Comparable<C>> boolean ge(C a,
                                                   C b,
                                                   boolean nullLast)
```
    This is a null-safe method that, given two comparable values a and b, tells if a >= b.
    This method considers null to be less than or greater than non-null based on the value of nullLast.
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    nullLast - tells if null is greater than non-null.
    
    Returns:
    
    true if a >= b.
  - gt
```
public static <C extends Comparable<C>> boolean gt(C a,
                                                   C b)
```
    This is a null-safe method that, given two comparable values a and b, tells if a > b.
    This method considers null to be less than non-null.
    This method is the same as CU.gt(a,b,false).
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    Returns:
    
    true if a > b.
  - gt
```
public static <C extends Comparable<C>> boolean gt(C a,
                                                   C b,
                                                   boolean nullLast)
```
    This is a null-safe method that, given two comparable values a and b, tells if a > b.
    This method considers null to be less than or greater than non-null based on the value of nullLast.
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    nullLast - tells if null is greater than non-null.
    
    Returns:
    
    true if a > b.
  - min
```
public static <C extends Comparable<C>> C min(C a,
                                              C b)
```
    This is a null-safe method that, given two comparable values a and b, returns the minimum value between them. If the values are equal returns a.
    This method considers null to be less than non-null.
    This method is the same as CU.min(a,b,false).
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    Returns:
    
    the minimum between a and b.
  - min
```
public static <C extends Comparable<C>> C min(C a,
                                              C b,
                                              boolean nullLast)
```
    This is a null-safe method that, given two comparable values a and b, returns the minimum value between them. If the values are equal returns a.
    This method considers null to be less than or greater than non-null based on the value of nullLast.
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    nullLast - tells if null is greater than non-null.
    
    Returns:
    
    the minimum between a and b.
  - max
```
public static <C extends Comparable<C>> C max(C a,
                                              C b)
```
    This is a null-safe method that, given two comparable values a and b, returns the maximum value between them. If the values are equal returns a.
    This method considers null to be less than non-null.
    This method is the same as CU.max(a,b,false).
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    Returns:
    
    the maximum between a and b.
  - max
```
public static <C extends Comparable<C>> C max(C a,
                                              C b,
                                              boolean nullLast)
```
    This is a null-safe method that, given two comparable values a and b, returns the maximum value between them. If the values are equal returns a.
    This method considers null to be less than or greater than non-null based on the value of nullLast.
    
    Type Parameters:
    
    C - type of the comparable values.
    
    Parameters:
    
    a - value to compare.
    
    b - value to compare.
    
    nullLast - tells if null is greater than non-null.
    
    Returns:
    
    the maximum between a and b.

Class CU

Method Summary

Methods inherited from class java.lang.Object

Method Detail

nullFirstNaturalOrderComparator

nullLastNaturalOrderComparator

nullSafeNaturalOrderComparator

lt

lt

le

le

eq

eq

ne

ne

ge

ge

gt

gt

min

min

max

max