How to capitalize only the first letter in the string using javascript?

Question

Hi i have a variable like below,

const str = 'passed'

now i want to capitalize only the first letter of the string. i can do it like below

const str2 = str.charAt(0).toUpperCase() + str.slice(1);

but is there any other better way to do the same using javascript?

could someone help me with this. thanks.