These are the commonly used regular expression syntax. Basic Regex. 1. Input of literal will match whatever is inputted. It is case sensitive. For example /s/ will match all the 's' in cats , sands but will not match "S" in Superman. 2. $ ^ * + ? . ( ) [ ] { } | \ The above are special characters , and must be escaped with a backslash. You can safely escape all special characters without errors. Spaces (" ") are not special characters , will be matched without backslash. 3. /./ A period means any character. If you want to find "." only . Use backslash /\./ 4. Regex will match any pattern you typed on it. If you typed /cat / it will match a "cat" followed by a space " " exactly. This is known as concatenation. The sequence of pattern matters. 5. If you want to choose one or the other, /(cat|dog|rabbit)/ it will choose either cat , dog or rabbit. This is called Alternation. 6. /launch/i If you want ...