Interfaces function hello1(person: { name: string; age: number }): void { console.log(`안녕하세요 ${person.name}입니다.`); } const p1: { name: string; age: number } = { name: "Mark", age: 39, }; hello1(p1); // { name: string; age: number } 대신 interface Person1 { name: string; age: number; } function hello1(person: Person1): void { console.log(`안녕하세요 ${person.name}입니다.`); } const p1: Person1 = { name: "M..