代码
提交代码
interface Triangle {
a: number;
b: number;
c: number;
area(this: Triangle): () => number;
}
let triangle: Triangle = {
a: 10,
b: 15,
c: 20,
area: function (this: Triangle) {
return () => {
const p = (this.a + this.b + this.c) / 2
return Math.sqrt(p * (p - this.a) * (p - this.b) *(p - this.c))
}
}
}
const myArea = triangle.area()
console.log(myArea())
运行结果