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]);

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);

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);

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));

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;

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;

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';

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);

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;

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());