Hong Kong stock exchange-listed Haidilao, a Chinese mainland hotpot chain, has introduced several snack varieties at night fairs in cities across the nation to cater to the burgeoning nighttime economy this summer.

This is part of the rapid expansion, both domestically and overseas, of Haidilao restaurant, which often sees long lines of diners waiting for a seat at its tables.

Haidilao recently launched a booth at a night fair in Qingdao, Shandong province, selling snacks such as fried pork and deep-fried dough sticks.

For Haidilao, at night fairs, most dishes carry the same price tag as those served in restaurants. However, customers do not have to pay for the bottom soup and seasoning.

Haidilao said the booths at night fairs are personalized to satisfy customer preferences and provide those who visit nighttime markets with a new casual dining experience.

At Nanjing East Road in Shanghai, Haidilao has set up a booth at the night market, mainly serving cold dishes. In fact, there is a Haidilao hotpot restaurant right across from the night fair.

In Taiyuan, Shanxi province, Haidilao has launched outdoor catering trucks to sell a variety of snacks, hotpot and beer late into the night. It has also set up some camping tables and chairs where diners can play board games.

"The external display of Haidilao indicates several considerations. It can help stimulate domestic consumption and the business growth of Haidilao as a company needs to fit in with the core demand of the new generation of young consumers," said Zhu Danpeng, an independent analyst tracking the food and beverages sector.

"The late-night dining business at restaurants and spending at bars are expected to see rapid growth in the next few years, as young consumers show continued demand for late-night consumption in China," Zhu said.

The night economy usually refers to activities that take place between 6 pm and 2 am, bringing economic gains. It covers sectors such as retail, transportation, catering, tourism and other entertainment, according to Trip.com Group, a leading online travel agency in China.

Meanwhile, as one of the first group of brands to try out full-time operations, some Haidilao restaurants are designed to operate for 22 hours based on their locations.

Other outlets offer a 30 percent discount at midnight for college students. Haidilao has also become a late-night cafeteria where many young people hang out.

Most Haidilao stores that operate until late in the night have witnessed a boom in customers.

From around 9 pm daily, Haidilao welcomes its first wave of late night guests. Later, with the closing of entertainment events such as concerts, people at the restaurants wait in line for a late-night dining experience, usually between Friday and Sunday.

Since 2016, China's nighttime economy has grown rapidly.

This year, sales during the nighttime are expected to exceed 48 trillion yuan ($6.6 trillion) in the country. Last year, the final contribution rate of consumer spending to GDP growth reached 76.2 percent, and nearly 60 percent of residents' consumption occurred at night, according to market consultancy iiMedia Research.