The chief executive of Facebook, Sheryl Sandberg, has paid deep tribute to the company’s founder, Mark Zuckerberg, for helping her cope with the sudden death of her husband in 2015.

Ms Sandberg’s husband, David Goldberg, collapsed and died suddenly while exercising at a resort in Mexico where the couple were holidaying.

Though they were both high-powered, new-media business leaders — Mr Goldberg had been the chief executive of the company Survey Monkey — they were also a famously devoted and traditional Jewish couple. To mark the shloshim, or 30th day of mourning after his death, Ms Sandberg wrote a long post on Facebook which drew thousands of responses from around the world.

Now — together with psychologist Adam Grant — she has developed her Facebook essay into a new book, Option B, in which she explores how to deal with grief.

In an interview with the Guardian last weekend, Ms Sandberg said that Mr Zuckerberg “is why I’m walking. Most of what [he and his wife Priscilla] did is not even in the book, because they did so much. When I felt so overwhelmed and so isolated and just needed to cry, I would grab him into his conference room and he would just sit there with me and be like, ‘we’re going to get through this and we want to get through it with you.’ He did it over and over.”

She also said that Mr Zuckerberg helped her to regain her self-confidence after she began second guessing her own decisions.