first letter capital javascript function code example

Example 1: javascript capitalize first letter

const lower = 'this is an entirely lowercase string';
const upper = lower.charAt(0).toUpperCase() + lower.substring(1);

Example 2: capitalize first carater js

const capitalize = (s) => {
  if (typeof s !== 'string') return ''
  return s.charAt(0).toUpperCase() + s.slice(1)
}

capitalize('flavio') //'Flavio'
capitalize('f')      //'F'
capitalize(0)        //''
capitalize({})       //''