/**
 * 将 JSON 字符串中的指定 keyPath 替换成 maskValue，其他内容不变
 * @param jsonStr 原始 JSON 字符串
 * @param keyPaths 点分路径字符串，如 ["xxx.token", "xxx.mobile"]
 * @param maskValue 替换值，默认是 "hidden"
 * @returns 替换后的 JSON 字符串
 *
 * @example
 * // 简单对象中隐藏字段
 * maskFieldInJsonStr('{"name":"John","token":"secret123"}', ['token'])
 * // => '{"name":"John","token":"hidden"}'
 *
 * // 嵌套对象中隐藏多个字段
 * maskFieldInJsonStr(
 *   '{"user":{"name":"John","token":"secret123","contact":{"mobile":"13800138000"}}}',
 *   ['user.token', 'user.contact.mobile']
 * )
 * // => '{"user":{"name":"John","token":"hidden","contact":{"mobile":"hidden"}}}'
 *
 * // 数组对象中隐藏字段
 * maskFieldInJsonStr(
 *   '{"users":[{"name":"John","token":"secret1"},{"name":"Jane","token":"secret2"}]}',
 *   ['users.0.token', 'users.1.token']
 * )
 * // => '{"users":[{"name":"John","token":"hidden"},{"name":"Jane","token":"hidden"}]}'
 *
 * // 复杂嵌套结构中隐藏字段
 * maskFieldInJsonStr(
 *   '{"data":{"users":[{"id":1,"token":"secret1","profile":{"mobile":"13800138000"}},{"id":2,"token":"secret2"}]}}',
 *   ['data.users.0.token', 'data.users.0.profile.mobile', 'data.users.1.token']
 * )
 * // => '{"data":{"users":[{"id":1,"token":"hidden","profile":{"mobile":"hidden"}},{"id":2,"token":"hidden"}]}}'
 */
export declare function maskFieldInJsonStr(jsonStr: string, keyPaths: string[], maskValue?: string): string;