javascript how to handle error code example

Example 1: try catch in javascript

try {
  // Try to run this code 
}
catch(err) {
  // if any error, Code throws the error
}
finally {
  // Always run this code regardless of error or not
  //this block is optional
}

Example 2: try catch javascript

try {

  alert('Start of try runs');  // (1) <--

  lalala; // error, variable is not defined!

  alert('End of try (never reached)');  // (2)

} catch(err) {

  alert(`Error has occurred!`); // (3) <--

}