Javascript: String validation using regex

Problem: Validate a string if its in Sentence case
Ex-1: Account
output: true
Ex-2: information
output: false

First create a regex to validate the string;

const regex = new RegExp('^[A-Z][a-z]*');

^ represents the start of the string
[A-Z] for validating the character should be in A to Z
similarly followed by smaller cases.

const str1 = 'Account';
const str2 = 'information';
const regex = new RegExp('^[A-Z][a-z]*');

console.log(regex.test(str1)); // outputs to true
console.log(regex.test(str2)); // outputs to false