charAt

const sentence = 'The quick brown fox jumps over the lazy dog.';

sentence.charAt(4);
// q

var anyString = 'Brave new world';
console.log("The character at index 0   is '" + anyString.charAt()   + "'");
// No index was provided, used 0 as default

console.log("The character at index 0   is '" + anyString.charAt(0)   + "'");
console.log("The character at index 1   is '" + anyString.charAt(1)   + "'");
console.log("The character at index 2   is '" + anyString.charAt(2)   + "'");
console.log("The character at index 3   is '" + anyString.charAt(3)   + "'");
console.log("The character at index 4   is '" + anyString.charAt(4)   + "'");
console.log("The character at index 999 is '" + anyString.charAt(999) + "'");

// The character at index 0   is 'B'
// The character at index 1   is 'r'
// The character at index 2   is 'a'
// The character at index 3   is 'v'
// The character at index 4   is 'e'
// The character at index 999 is ''