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In this tutorial, we will learn about Java 8 LongPredicate interface.

LongPredicate Interface :-

LongPredicate ( java.util.function.LongPredicate ) is a functional interface that has one abstract method and three default method declared in it. This interface is a specialised form of Predicate interface.

Abstract method :- 

boolean  test ( long value ) :- The abstract method test ( long value ) is a functional method. It accepts one long value as an argument and return boolean value. It represents a conditional operation, where a passed long value is tested against a specific long value to give a boolean ( True or False ) result.

Default method :-  

1. default  LongPredicate<T>  and ( LongPredicate <? super T > other ) :- It returns a longpredicate that represents short circuiting logical AND of this longpredicate ( longpredicate on which method is called ) and another ( passed as an argument ).
2. default LongPredicate<T>  or ( LongPredicate <? super T > other ) :- It returns a longpredicate that represents short circuiting logical OR of this longpredicate ( longpredicate on which method is called ) and another ( passed as an argument ).
3. default LongPredicate<T>  negate (  ) :- It returns a longpredicate that represents logical negation of this longpredicate ( longpredicate on which method is called ).

Reference :-  LongPredicate Interface JavaDocs 

Example :- 

This example will show you, how to create and call different methods of a longpredicate interface.

  public static void main(String[] args){
 
    LongPredicate longPredicate1 = ( x ) -> { if( x == 800 ){ return true;
                                              }else{ return false; }};
    // Example of test method
    boolean result = longPredicate1.test(800);
    System.out.println(result);
 
    // Example of negate method
    boolean result3 = (longPredicate1.negate()).test(800);
    System.out.println(result3);
 
    LongPredicate longPredicate2 = ( x ) -> { if( x == 900 ){ return true;
                                              }else{ return false; }};
 
    // Example of and method
    boolean result1 = longPredicate1.and(longPredicate2).test(800);
    System.out.println(result1);
 
    // Example of or method
    boolean result2 = longPredicate1.or(longPredicate2).test(800);
    System.out.println(result2);
 
  }  

Result :- 

true
false
false
true

That’s all for Java 8 LongPredicate Interface. If you liked it, please share your thoughts in comments section and share it with others too.