World Tour [JavaScript]

function worldTour(array) {
  let start = array.shift();

  for (let i = 0; i < array.length; i++) {
    let command = array[i].split(":");
    let token = command[0];

    if (token === "Add Stop") {
      let startIndex = Number(command[1]);
      let destination = command[2];

      if (startIndex >= 0 && startIndex < start.length) {
        start = start.slice(0, startIndex) + destination + start.slice(startIndex, start.length);
      }

      console.log(start);
    } else if (token === "Remove Stop") {
      let startIndex = Number(command[1]);
      let endIndex = Number(command[2]);

      if (startIndex >= 0 && endIndex < start.length) {
        let split = start.substring(startIndex, endIndex + 1);
        start = start.replace(split, "");
      }

      console.log(start);
    } else if (token === "Switch") {
      let oldString = command[1];
      let newString = command[2];

      if (start.includes(oldString)) {
        start = start.split(oldString).join(newString);
      }

      console.log(start);
    } else if (token === "Travel") {
      console.log(`Ready for world tour! Planned stops: ${start}`);
    }
  }
}