接口和对象类型

对象类型

声明与定义

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interface Person {
    name:string,
    age:number
}

let person:Person = {
    name:'lwh',
    age:18
}

重名接口可合并

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interface Student {
    name:string
}
interface Student {
    age:number
}

let student:Student = {
    name:'hwl',
    age:81
}

继承

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interface Pupil extends Student{
    grade:number
}

let pupil:Pupil = {
    name:'sb',
    age:11,
    grade:4
}

可选属性

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interface Choice {
    a:string,
    b?:number
}

let choice:Choice = {
    a:'a'
}

任意属性

可参考https://juejin.cn/post/6855449252785717256

如果需要一个接口需要有任意的属性签名，这时就会用到任意属性。

任意属性有两种定义的方式：一种属性签名是 string 类型的，另一种属性签名是 number 类型的。

string类型任意属性

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interface A {
    [prop:string]:any
}

let aa:A = {
    a:'hello',
    b:114514
}

number类型任意属性

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interface B {
    [prop:number]:number
}

let bb:B = {
    1:22333,
    2:114514,
    100:99
}

console.log(bb[1])
console.log(bb[100])

输出

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22333
99

只读属性

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interface Read {
    a:number,
    readonly b:string
}

let read:Read = {
    a:114514,
    b:'lwh'
}

添加函数

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interface Student {
    name:string
}
interface Student {
    age:number,
    score:number,
    exam():number
}

let student:Student = {
    name:'hwl',
    age:81,
    score:90,
    exam(): number {
        this.score = this.score + 1;
        return this.score;
    }
}