RegularExpression

WMA link

RegularExpression[“regex”]

represents the regex specified by the string "regex".

• • StringSplit["1.23, 4.56  7.89", RegularExpression["(\\s|,)+"]]

RegularExpression just wraps a string to be interpreted as a regular expression, but are not evaluated as stand alone expressions:

• • RegularExpression["[abc]"]