typescript lessons

TypeChallenges.ts

// 11. 元组转换为对象
const tuple = ['tesla', 'model 3', 'model X', 'model Y'] as const

type TupleToObject<T extends readonly any[]> = {[P in T[number]]: P}

type result = TupleToObject<typeof tuple>

typescript-lesson-one.ts

// 同一类型的不同表述
let scores: number[] = [1, 2, 3, 4, 99]

let anotherScores: Array<number> = [1, 3, 4, 6, 7]

scores = anotherScores // ✅
// anotherScores = scores

/**
 * A pure function that add two numbers
 * 
 * @param {number} x adder param **one**
 * @param {number} y adder param **two**
 * 
 */
function add(x: number, y: number): number {
    return x + y
}

add(1, 2)

// 接口，duck type
interface Employee {
    title: string
    name: string
    age: number
}

let developer = {
    title: 'Frontend-Developer',
    name: 'xiongchengqing',
    age: 30,
    editor: 'VSCODE'
}

let juniorEmployee: Employee = developer // ✅ duck type
let seniorEmployee: Employee = {
    title: 'Frontend-Developer',
    name: 'jiangjun',
    age: 30,
    editor: 'WEBSTORM'
} // ❌ 直接将对象字面量赋值不行