Walmart’s many efforts to bolster its food shopping services — including letting customers order online and pick up in person, expanding its home delivery of groceries, even experimenting with robots — appear to be paying off, the company said Thursday.

The company, the largest grocer in the United States with a 23 percent share of the market, said the grocery division’s performance last quarter was its best in nine years, propelling a crucial sales measure to its largest increase in a decade.

The results pushed Walmart’s stock up more than 10 percent.

Walmart said Thursday it expected to offer home delivery of groceries to 40 percent of the U.S. population by the end of 2018. It expanded its service that provides curbside pickup of food orders to 1,800 stores.

This month, Walmart’s battle with Amazon escalated after the online giant announced a similar pickup service at Whole Foods stores.

Walmart’s online grocery strategy required the company to combine its inventory with a digital infrastructure that has been uninspiring to customers.

After redesigning the website, e-commerce sales in the United States increased 40 percent in the second quarter from a year earlier, an improvement from the 33 percent upswing it reported over the previous three-month period.