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• ???? ??
• ??? ??? ?? ?? ?? ??
• ?? ??? ???? ?? ?? ?? ??(< 0 || > 100)

??? 1: ????? ?? ??

??? ??? ???? ?? ??????? ?? ??? ???? ??? ?? ???? ??? ? ? ?? ??? ????? ?? ??? ??????.

type Subject = "english" | "maths";

interface IStudent {
  name: string;
  marks: Record<Subject, number>;
}

// Receive Input
const studentInput: IStudent = {
  name: "John",
  marks: {
    english: 100,
    maths: 100,
  },
};

// Step1: Validate the provided marks
Object.keys(studentInput.marks).forEach((subjectName) => {
  const mark = studentInput.marks[subjectName as Subject];
  if (mark > 100 || mark < 0) {
    throw new Error(`invlid mark found`);
  }
});

// Step2: find the total marks
const totalMarks = Object.keys(studentInput.marks).reduce(
  (accumulator: number, current: string) =>
    studentInput.marks[current as Subject] + accumulator,
  0
);

// Step3: find the average
const average = totalMarks / Object.keys(studentInput.marks).length;

// Step4: find the result
const boolResult = average > 40;

// Step 5: print result
console.log(boolResult);
console.log(average);

??? 1? ??:

??? ??? ???? ??? ????? ?? ??? ? ?? ??? ????. ? ?? ?? ??

1. ??? ?? ??? ? ????? ??? ???? ?? ???? ??? ??? ? ????.
2. ???? ??? ????? ?? ??? ???? ??? ???? ???? ?????. ???? ??? ??? ??? ????? ?? ??? ?? ?? ???? ???.
3. ??? ???? ??? ????? ? ??????. ??? ???? ?? ?? ???? ?? ?? ?? ??? ??? ? ????.

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1. ??? ? ??? ?? ??? ??
2. ??? ??? ??

??? 2: ??? ??

type SubjectNames = "english" | "maths";

interface IStudent {
  name: string;
  marks: Record<SubjectNames, number>;
}

class ResultCalculator {
  protected student: IStudent;
  constructor(student: IStudent) {
    this.student = student;
  }

  isPassed(): boolean {
    let resultStatus = true;
    Object.keys(this.student.marks).forEach((subject: string) => {
      if (this.student.marks[subject as SubjectNames] < 40) {
        resultStatus = false;
      }
    });
    return resultStatus;
  }

  getAverage(): number {
    this.validateMarks();
    return this.totalMarks() / this.subjectCount();
  }

  private validateMarks() {
    Object.keys(this.student.marks).forEach((subject: string) => {
      if (
        this.student.marks[subject as SubjectNames] < 0 ||
        this.student.marks[subject as SubjectNames] > 100
      ) {
        throw new Error(`invalid mark`);
      }
    });
  }

  private totalMarks() {
    return Object.keys(this.student.marks).reduce(
      (acc, curr) => this.student.marks[curr as SubjectNames] + acc,
      0
    );
  }

  private subjectCount() {
    return Object.keys(this.student.marks).length;
  }
}

// Receive Input
const a: IStudent = {
  name: "jingleheimer schmidt",
  marks: {
    english: 100,
    maths: 100,
  },
};

// Create an encapsulated object
const result = new ResultCalculator(a);

// Perform operations & print results
console.log(result.isPassed());
console.log(result.getAverage());

? ????? ????

1. ??? totalMarks, subjectCount, verifyMarks ? ?? ?? ??? ???? ??? ??? ????? ??? ? ????.

2. ??? ??? ?? ??? ?? ??? ?????.

? ??? OOP - ???? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!