Function assert

Parameters

• condition: any
• Optionalmessage: string

  The message to set in the error that is thrown

  class ProblemLogger {
    problem?: string;
  
    log() {
      assert(this.problem, "You must set problem before logging it");
  
      // now typescript knows `this.problem` is truthy, so we can safely call methods on it
      console.log(problem.toUpperCase());
    }
  }
  Copy