count.md

[literable].count

Returns the number of elements in a sequence.

Overloads

• count(): Returns the number of elements in a sequence.
• count(predicate): Returns a number that represents how many elements in the specified sequence satisfy a condition.

count()

Returns the number of elements in a sequence.

Parameters

• result: The number of elements in the input sequence.

Examples

The following code example demonstrates how to use Count to count the elements in an array.

const Literable = require('literable');

const fruits = [ 'apple', 'banana', 'mango', 'orange', 'passionfruit', 'grape' ];

const numberOfFruits = Literable.from(fruits).count();
console.log(`There are ${numberOfFruits} fruits in the collection.`);

// This code produces the following output:
//
// There are 6 fruits in the collection.

count(predicate)

Returns a number that represents how many elements in the specified sequence satisfy a condition.

Parameters

• predicate: A function to test each element for a condition.
• result: A number that represents how many elements in the sequence satisfy the condition in the predicate function.

Examples

The following code example demonstrates how to use Count(predicate) to count the elements in an array that satisfy a condition.

const Literable = require('literable');

const pets = Literable.from([
    { name: 'Barley', vaccinated: true },
    { name: 'Boots', vaccinated: false },
    { name: 'Whiskers', vaccinated: false },
]);

const numberUnvaccinated = pets.count(p => p.vaccinated == false);
console.log(`There are ${numberUnvaccinated} unvaccinated animals.`);

// This code produces the following output:
//
// There are 2 unvaccinated animals.