throwing error in javascript code example

Example 1: js throw error

throw new Error('Whoops!')

Example 2: javascript how to raise the error

if (..condition..) {
    throw 'Error message';
  }

Example 3: try catch throwing error in javascript

let json = '{ "age": 30 }'; // incomplete data

try {

  let user = JSON.parse(json); // <-- no errors
  alert( user.name ); // no name!

} catch (e) {
  alert( "doesn't execute" );
}