how to extract string in javascript code example

Example 1: how to get the first character of a string in javascript

let str = 'John Wick'
let firstChar = str.charAt(0) 
console.log(firstChar); // "J"

Example 2: javascript how to get middle letters of a string

function extractMiddle(str) {

        var position;
        var length;

        if(str.length % 2 == 1) {
            position = str.length / 2;
            length = 1;
        } else {
            position = str.length / 2 - 1;
            length = 2;
        }

        return str.substring(position, position + length)
    }

    console.log(extractMiddle("handbananna"));