Sep 9, 2021 JavaScript
How to check if all items in an array are equal in JavaScript

In this Article we will go through how to check if all items in an array are equal 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 areEqual = arr => arr.length > 0 && arr.every(item => item === arr[0]);

Sep 9, 2021 JavaScript
How to check if a string is an octal number in JavaScript

In this Article we will go through how to check if a string is an octal number 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 isOctal = str => /^(0o)?[0-7]+$/i.test(str);

Sep 9, 2021 JavaScript
How to check if all array elements are equal to a given value in JavaScript

In this Article we will go through how to check if all array elements are equal to a given value 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 isEqual = (arr, value) => arr.every(item => item === value);

Sep 9, 2021 JavaScript
How to check if an array contains a value matching some criterias in JavaScript

In this Article we will go through how to check if an array contains a value matching some criterias 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 contains = (arr, criteria) => arr.some(v => criteria(v));

Sep 9, 2021 JavaScript
How to check if an array is not empty in JavaScript

In this Article we will go through how to check if an array is not 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 isNotEmpty = arr => Array.isArray(arr) && Object.keys(arr).length > 0;

Sep 9, 2021 JavaScript
How to check if an array is subset of other array in JavaScript

In this Article we will go through how to check if an array is subset of other 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:

// Check if `b` is subset of `a`
const isSubset = (a, b) => (new Set(b)).size === (new Set(b.concat(a))).size;

Sep 9, 2021 JavaScript
How to check if an object is a promise in JavaScript

In this Article we will go through how to check if an object is a promise 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 isPromise = obj => !!obj && (typeof obj === 'object' || typeof obj === 'function') && typeof obj.then === 'function';

Sep 9, 2021 JavaScript
How to check if an object is an array in JavaScript

In this Article we will go through how to check if an object is 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 isArray = obj => Array.isArray(obj);

Sep 9, 2021 JavaScript
How to check if an object is empty in JavaScript

In this Article we will go through how to check if an object 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 = obj => Reflect.ownKeys(obj).length === 0 && obj.constructor === Object;

Sep 9, 2021 JavaScript
How to calculate the number of months between two dates in JavaScript

In this Article we will go through how to calculate the number of months between two dates 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 monthDiff = (startDate, endDate) => Math.max(0, (endDate.getFullYear() - startDate.getFullYear()) * 12 - startDate.getMonth() + endDate.getMonth());