Unlike JavaScript‘s const variable declarations, TypeScript allows you to create fully immutable types. In this lesson, we learn how to create immutable types in TypeScript with the help of as const
const user = { name: ‘xxx‘, education: { degree: ‘MSc‘ } } as const const users = [ ‘a‘, ‘b‘ ] as const user.education.degree = "BSc" users.push(‘c‘)
[TypeScript] as const, force immutability for Object type
原文：https://www.cnblogs.com/Answer1215/p/12364838.html