Within hours of the announcement that he had been named the new host of “The Daily Show,” the comedian Trevor Noah was subjected to the full scrutiny of the Internet. As potential audience members scoured his past work and social media presence for more clues to Mr. Noah, a South African comedian, they uncovered many posts on his Twitter account that they deemed offensive to women or Jews.

Comedy Central announced on Monday that Mr. Noah, 31, would succeed Jon Stewart as anchor of “The Daily Show,” its satirical late-night news program, when Mr. Stewart steps down this year. Though Mr. Noah has performed stand-up comedy around the world, he is not widely known in the United States, and he had appeared as an on-air contributor to “The Daily Show” only three times before being named as host.

On Twitter, where he has had an account since 2009 and accumulated more than two million followers, Mr. Noah often posts irreverent statements that reflect his interests in popular culture, global politics and issues of race. As with many comedians, Mr. Noah’s jokes can test the boundaries of what is socially permissible and what is in bad taste.

In several posts, Mr. Noah came across as mocking or derisive of women. In one from 2011, he writes: “Oh yeah the weekend. People are gonna get drunk & think that I’m sexy!” a quote that he attributes to “fat chicks everywhere.”