js change value based on select box code example

Example 1: javascript select change selected

const options = Array.from(select.options);
options.forEach((option, i) => {
  if (option.value === use_id) select.selectedIndex = i;
});

Example 2: js select on change value

document.getElementById('my-select').addEventListener('change', function() {
  console.log('You selected: ', this.value);
});