Wilshere - whose contract ran out at the end of June - made a decision to look for a new club when new Gunners manager Unai Emery told him he would not be a first choice next season.
In a statement on the website Wilshere said, "It feels good, it feels special". After speaking with the manager and those at the club I knew my future was at the London Stadium and I can't wait to get going now.
"People will have seen the picture of me in a West Ham shirt and I've got good memories of my childhood supporting West Ham, watching them at Upton Park".
Manuel Pellegrini wants his West Ham side to play attacking football and pushed to sign the midfielder despite some concern within the club over his injury record. Let us know in the comment section below.
The Most Expensive and Powerful MacBook Pro Now Costs $6,898
The Verge , meanwhile, notes that the new keyboard was created to be quieter, not to address complaints about reliability. There aren't many details available, but previous rumors have suggested that Apple may be upgrading the MacBook Air.
Hampered by injuries in the past, the England worldwide made 20 league appearances in the 2017-18 season but now starts a fresh chapter of his career.
Manchester United have been the club predominantly linked with him, as they are with the vast majority of breathing humans, but West Ham's recruitment drive this summer looks set to finally claim him.
"I think it was a number of things", he said.
West Ham are trying to secure deals for new players as per the instructions of latest managerial appointment Manuel Pellegrini, who is thought to be interested in overhauling the current squad as much as possible in this transfer window.
Eight of 13 young footballers rescued from Thai cave so far
A witness near the cave told the Reuters news agency that medical workers carried four people to emergency rescue vehicles. The aide, Sitthichai Klangpattana, didn't comment on the boys' health or say how well the operation has gone.
"Jack is a player with excellent technical ability, combined with great energy and commitment, and has proven his quality both in the Premier League and at global level", he told the club's website.
The 26-year-old midfielder arrived the London club after he chose to leave Arsenal after 17 years when his contract expired last month.
But he was still left out of Gareth Southgate's World Cup squad and will be hoping that more regular playing time in the Premier League will put him back in contention for the England team.
Ukraine worldwide Andriy Yarmolenko became the latest addition this week as he signed from Borussia Dortmund for an undisclosed fee.
US says to slap tariffs on extra $200 billion of Chinese imports
That prompted fears Beijing might go beyond matching USA import tax increases by harassing American companies in China. Senate Finance Committee Chairman Orrin Hatch said the announcement "appears reckless and is not a targeted approach".