TS1109

error TS1109: Expression expected.

Broken Code ❌

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const lastName = throw new Error('Missing last name');

Fixed Code ✔️

Any snippet of code that evaluates to a value is an expression. Any snippet of code that performs an action is a statement. We need a statement to throw an error inside:

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const lastName = undefined;
if (!lastName) {
  throw new Error('Missing last name');
}