Sep 9, 2021 JavaScript
How to curry a function in JavaScript

In this Article we will go through how to curry a function 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 curry = (fn, ...args) => fn.length <= args.length ? fn(...args) : curry.bind(null, fn, ...args);

Sep 9, 2021 JavaScript
How to delay the evaluation of a function in JavaScript

In this Article we will go through how to delay the evaluation of a function 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:

// returns a new version of `fn` that returns values as lazy evaluable
const thunkfy = fn => (...args) => () => fn(...args);

Sep 9, 2021 JavaScript
How to execute a function once in JavaScript

In this Article we will go through how to execute a function once 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 once = fn => ((ran = false) => () => ran ? fn : (ran = !ran, fn = fn()))();

Sep 9, 2021 JavaScript
How to flip the arguments of a function in JavaScript

In this Article we will go through how to flip the arguments of a function 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:

// Reverse the order of arguments
const flip = fn => (...args) => fn(...args.reverse());

// For binary functions
const flip = fn => (b, a) => fn(a, b);

Sep 9, 2021 JavaScript
How to memoize a function in JavaScript

In this Article we will go through how to memoize a function 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 memoize = fn => ((cache = {}) => arg => cache[arg] || (cache[arg] = fn(arg)))();

Sep 9, 2021 JavaScript
How to logical xor operator in JavaScript

In this Article we will go through how to logical xor operator 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:

// returns `true` if one of the arguments is truthy and the other is falsy

const xor = (a, b) => (a && !b) || (!a && b);

Sep 9, 2021 JavaScript
How to partially apply a function in JavaScript

In this Article we will go through how to partially apply a function 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 partial = (fn, ...a) => (...b) => fn(...a, ...b);

Sep 9, 2021 JavaScript
How to check if an element is a descendant of another in JavaScript

In this Article we will go through how to check if an element is a descendant of another 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 isDescendant = (child, parent) => parent.contains(child);

Sep 9, 2021 JavaScript
How to check if an element is focused in JavaScript

In this Article we will go through how to check if an element is focused 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 hasFocus = ele => (ele === document.activeElement);

Sep 9, 2021 JavaScript
How to check if the touch events are supported in JavaScript

In this Article we will go through how to check if the touch events are supported 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 touchSupported = () => ('ontouchstart' in window || window.DocumentTouch && document instanceof window.DocumentTouch);