检查TypeScript对象的属性是否都为空

interface MyObject {
    prop1?: string;
    prop2?: number;
    prop3?: boolean;
}

function areAllPropertiesEmpty(obj: MyObject): boolean {
    for (const key in obj) {
        if (obj.hasOwnProperty(key)) {
            if (obj[key] !== null && obj[key] !== undefined && obj[key] !== '') {
                return false;
            }
        }
    }
    return true;
}

const obj1: MyObject = {};
const obj2: MyObject = { prop1: '' };
const obj3: MyObject = { prop1: 'value' };

console.log(areAllPropertiesEmpty(obj1)); // true
console.log(areAllProperties.empty(obj2)); // true
console.log(areAllPropertiesEmpty(obj3)); // false

function isString(value: any): value is string {
    return typeof value === 'string';
}

if (isString(obj.prop1)) {
    // obj.prop1 在这里是 string 类型
}

const value = obj?.prop1;