Stream method count() with different data type in Java

A stream method count() used to determine a number of elements in this stream. It returns long value that represents a count of elements in the stream.

Syntax

 1 long count()

return : It returns number of elements present in the stream object.

count() with number

 1 package com.java;
 2 
 3 import java.util.Arrays;
 4 import java.util.List;
 5 
 6 public class Main {
 7 
 8     public static void main(String[] args) {
 9 
 10         List<Integer> list = Arrays.asList(12, 30, 4, 55, 3, 10);
 11         System.out.println("Original list : "+ list);
 12 
 13         long res = list.stream().count();
 14         System.out.println("An elements in string is : "+ res);
 15     }
 16 }

In the above example, a list of number is declared and stream using collection method that returns stream object. A stream method count() is called that returns number of elements in the stream. The result is assigned to the variable and print.

Output

 1 Original list : [12, 30, 4, 55, 3, 10]
 2 An elements in string is : 6

count() with string

 1 package com.java;
 2 
 3 import java.util.Arrays;
 4 import java.util.List;
 5 
 6 public class StringExp {
 7 
 8     public static void main(String[] args) {
 9 
 10         List<String> elements = Arrays.asList("Hi", "Hello", "world",
 11                 "in", "Java");
 12         // print original list
 13         System.out.println("An original list elements : " + elements);
 14 
 15         long res = elements.stream().count();
 16         System.out.println("An elements in stream is : " + res);
 17     }
 18 }

In the above example, a list of stream is declared and stream using collection method stream() that returns stream object. A stream object count called that returns long value that specifies an elements in the stream.

Output

 1 An original list elements : [Hi, Hello, world, in, Java]
 2 An elements in stream is : 5

count() with Custom object with filter

 1 package com.java;
 2 
 3 import java.util.Arrays;
 4 import java.util.List;
 5 
 6 public class OrderExp {
 7     public static void main(String[] args) {
 8         Product pd1 = new Product(100, "Phone", 10, 120000.32);
 9         Product pd2 = new Product(101, "TV", 7, 48730.51);
 10         Product pd3 = new Product(102, "Laptop", 10, 439482.05);
 11         Product pd4 = new Product(103, "Watch", 7, 10000.44);
 12 
 13         List<Product> products = Arrays.asList(pd1, pd2, pd3, pd4);
 14 
 15         long res = products.stream()
 16                         .filter(prd -> prd.getQuantity() > 8)
 17                                 .count();
 18 
 19         System.out.println("Product with more than 8 quantity is : " + res);
 20     }
 21 }

In the above example, a list of product is created and stream using collection method stream that return stream object. A stream method filter() called that filter elements whose quantity is less than equal to 8 and return stream. A resulting stream elements count returned by the count() method and print.

Output

 1 Product with more than 8 quantity is : 2

Related options for your search

TypedArray instance methods in Javascript

Pandas DataFrame function corrwith() in Python

Pandas core groupby DataFrameGroupBy function corrwith() in Python

Country currency code

Country locales and options

Basic or Primitive data types in Javascript

Data type in Javascript

Basic or primitive data type in C language

Data type in C language

Data type in Golang

Built-in data type in Python

Stream count() method in java 8

String startsWith() function in Javascript

String endsWith() function in Javascript

With keyword in Javascript

String method startsWith() in java

Check if string starts with prefix in Golang

String method endswith() in Python

String method startswith() in Python

Disclaimer

About us