StringFreeQ

StringFreeQ["string", patt]
yields True if no substring in "string" matches the string expression patt, and yields False otherwise.

StringFreeQ["string", {patt₁, patt₂, ...}]
yields True if no substring matches any of the patt_i.

StringFreeQ[{s₁, s₂, ...}, p]
gives the list of results for each of the s_i.

The string expression patt can contain any of the objects specified in the notes for StringExpression.

Setting the option IgnoreCase->True makes StringFreeQ treat lowercase and uppercase letters as equivalent.

Test whether a string pattern contains a substring matching the pattern:

Check that a string is free of "a":

New in 5.1