TS homework 2

1.ts

type Identifier = string | number

// =======

const ReadOperation: symbol = Symbol('Read')
const WriteOperation: symbol = Symbol('Write')
const UpdateOperation: symbol = Symbol('Update')
type Operations = typeof ReadOperation | typeof WriteOperation | typeof UpdateOperation

// =======

type Grades = number[]
type GradeStatus = 'pass' | 'fail'

// =======

type CalculateArea = {
    (radius: number): number
    (width: number, height: number): number
    (a: number, b: number, c: number): number
}

const caclulateArea: CalculateArea = function (...args: number[]) {
    switch (args.length) {
        case 1: {
            const [radius] = args

            return Math.PI * Math.pow(radius, 2)
        }

        case 2: {
            const [width, height] = args

            return width * height
        }

        case 3: {
            const [a, b, c] = args
            const s = (a + b + c) / 2

            return Math.sqrt(s * (s - a) * (s - b) * (s - c))
        }

        default: {
            throw new Error('arguments mismatch')
        }
    }
}

// =======

type Template = `${bigint}${'px' | '%'}`