javascript regex of a javascript string

Question

I need to match a javascript string, with a regular expression, that is a string enclosed by single quote and can only contain a backslashed single quote.

The exampl

Answer 1

it's not that hard...

Also, you need to detect some other possible chars sequences like \n, \r or \\, breaking a line without escaping is not valid in javascript, you must use the \n sequence.

/^'([^\\'\n\r]|\\'|\\n|\\r|\\\\)*'$/

In execution:

var sample = ["'abcdefg'", // Valid
              "'abc\\'defg'", // Valid
              "'abc\\'de\\'fg'", // Valid
              "'abc\\'\\r\\nde\\'fg'", // Valid
              "'abc\\'\r\nde\\'fg'", // Invalid
              "'abc'def'" // Invalid
             ];
for(var i = 0; i < sample.length; i++)
    console.log(sample[i].match( /^'([^\\'\n\r]|\\'|\\n|\\r|\\\\)*'$/ ));

1. ^ tell to the matcher that the next condition must match the begining of the string
2. ' will match the ' delimiter
3. ( opens a group
4. [^\\'\n\r] matches anything different from \ and ', and will not match the special \n and \r characters
5. | if the condition above didn't match anything, the right side of | will be tested
6. \\' will match \'
7. \\n will match a \n literal string
8. |\\r or will match a \r literal string
9. |\\\\ or will match a \\ literal string
10. )* close the group and allow it to repeat multiple times and allow it to do not exist (empty string for example)
11. ' will match the final ' delimiter
12. $ tell to the matcher that this must be the and of the string