Regex for replacing a single-quote with two single-quotes

Question

I'm running into an issue that I think is being caused by needing to double-up on some single quotes inside a string. However, JS's string.replace uses RegEx, and I've never built a RegEx by hand.

Can someone help me build a RegEx to find a single quote and replace it with two single quotes?

Answer 1

str.replace(/'/g, "''");

Be sure to use the global match flag (g) so that you replace any and all occurrences in the string. More info here.

Answer 2

Try this:

yourstring = yourstring.replace(/'/g, "''")

Answer 3

JS's string.replace uses RegEx

Not necessarily:

var str = "O'Reilly's books";
alert(str.replace("'", "''", 'g'));

MDC's String replace reference:

The pattern can be a string or a RegExp

Mmm, my code above doesn't seem to work on IE6, so that will be:

str.replace(/'/g, "''")

like the others said, but using regexes for such simple operation is overkill.

Answer 4

I don't know the exact syntax, but you can find that out yourself:

str.replace(/(?!')'(?!')/g, "''");

Haven't tested this yet, but if it works, it also takes care of only replacing occurances of one single quote in a row. The g modifier is necessary for replacing all ocurrences.

Answer 5

js> s = "abc'def'xyz"
abc'def'xyz
js> s.replace(/'/g, "''")
abc''def''xyz

Answer 6

Note that if you don't want to use RegExp (and there are often good reasons not to), the idiom for a simple string replacement is:

str.split("'").join("''")

Although the RegExp version is typically marginally faster, the string version can be a win when you don't know if there might be regex-special characters (like .) in the search string.