In this Article we will go through how to check if a number is negative 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 isNegative = number => Math.sign(number) === -1;

In this Article we will go through how to check if a number is odd 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 isOdd = number => number % 2 !== 0;

In this Article we will go through how to check if a number is positive 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 isPositive = number => Math.sign(number) === 1;

In this Article we will go through how to check if a string contains lower case characters 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 containsLowerCase = str => str !== str.toUpperCase();

In this Article we will go through how to check if a string contains only digits 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 isNumeric = str => !/[^0-9]/.test(str);

In this Article we will go through how to check if a string contains only letters and numbers 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 isAlphanumeric = str => /^[0-9A-Z]+$/i.test(str);

In this Article we will go through how to check if a string contains only ascii characters 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 isAscii = str => /^[\x00-\x7F]+$/.test(str);

In this Article we will go through how to check if a date is today 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 isToday = (date) => date.toISOString().slice(0, 10) === new Date().toISOString().slice(0, 10);

In this Article we will go through how to check if a date occurs in the current year 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 isCurrentYear = (date) => date.getUTCFullYear() === new Date().getUTCFullYear();

In this Article we will go through how to check if a flat array has duplicate values 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 hasDuplicateValues = arr => new Set(arr).size !== arr.length;