Tells the regex engine to treat the metacharacter as a literal character.
To match a literal period, you would use /\./
An example would be /9\.00/ matches “9.00”, but not “9500” or “9-00”.
Match a backslash by escaping a backslash with \\
Escaping is only done for metacharacters.
Literal characters should never be escaped.
Quotation marks are not metacharacters and do not need to be escaped.
/h.._export.txt/g would match “his_export.txt” and “her_export.txt”
Another good example is /resume.\.txt/ which will match “resume1.txt”, “resume2.txt” and then not match “resume3_txt.zip”, because it then matches the number and not the _ after it.