In this Article we will go through how to count by the properties of an array of objects only using single line of code in JavaScript. This is a one-line JavaScript code snippet that uses one of the most popular ES6 features => Arrow Function.

Let's define this short function:

const countBy = (arr, prop) => arr.reduce((prev, curr) => (prev[curr[prop]] = ++prev[curr[prop]] || 1, prev), {});

In this Article we will go through how to count the occurrences of a value in an array only using single line of code in JavaScript. This is a one-line JavaScript code snippet that uses one of the most popular ES6 features => Arrow Function.

Let's define this short function:

const countOccurrences = (arr, val) => arr.reduce((a, v) => (v === val ? a + 1 : a), 0);

In this Article we will go through how to count the occurrences of array elements only using single line of code in JavaScript. This is a one-line JavaScript code snippet that uses one of the most popular ES6 features => Arrow Function.

Let's define this short function:

const countOccurrences = arr => arr.reduce((prev, curr) => (prev[curr] = ++prev[curr] || 1, prev), {});

In this Article we will go through how to create an array of cumulative sum only using single line of code in JavaScript. This is a one-line JavaScript code snippet that uses one of the most popular ES6 features => Arrow Function.

Let's define this short function:

const accumulate = arr => arr.map((sum => value => sum += value)(0));

In this Article we will go through how to cast a value as an array only using single line of code in JavaScript. This is a one-line JavaScript code snippet that uses one of the most popular ES6 features => Arrow Function.

Let's define this short function:

const castArray = value => Array.isArray(value) ? value : [value];

In this Article we will go through how to check if an array is empty only using single line of code in JavaScript. This is a one-line JavaScript code snippet that uses one of the most popular ES6 features => Arrow Function.

Let's define this short function:

const isEmpty = arr => !Array.isArray(arr) || arr.length === 0;