Get Object Value from String Path

const obj = {
  a: {
    b: {
      c: [1, 2, 3],
    },
  },
};

console.log(get(obj, "a.b.c"));
console.log(get(obj, "a.b.c.0"));
console.log(get(obj, "a.b.c[1]"));
console.log(get(obj, ["a", "b", "c", "2"]));
console.log(get(obj, "a.b.c[3]"));
console.log(get(obj, "a.c"));

// [ 1, 2, 3 ]
// 1
// 2
// 3
// undefined
// undefined

function get(object, stringPath) {
  if (stringPath === "" || stringPath.length === 0) {
    return;
  }

  const excludeCharacters = ["[", "]", "."];
  const keys = [];

  for (let i = 0; i < stringPath.length; i++) {
    if (!excludeCharacters.includes(stringPath[i])) {
      keys.push(stringPath[i]);
    }
  }

  return keys.reduce((obj, key) => obj[key], object);
}