WIP

9-regular-expressions/13-regexp-alternation/03-match-quoted-string/solution.md

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+The solution: `pattern:/"(\\.|[^"\\])*"/g`.
+
+Step by step:
+
+- First we look for an opening quote `pattern:"`
+- Then if we have a backslash `pattern:\\` (we technically have to double it in the pattern, because it is a special character, so that's a single backslash in fact), then any character is fine after it (a dot).
+- Otherwise we take any character except a quote (that would mean the end of the string) and a backslash (to prevent lonely backslashes, the backslash is only used with some other symbol after it): `pattern:[^"\\]`
+- ...And so on till the closing quote.
+
+In action:
+
+```js run
+let reg = /"(\\.|[^"\\])*"/g;
+let str = ' .. "test me" .. "Say \\"Hello\\"!" .. "\\\\ \\"" .. ';
+
+alert( str.match(reg) ); // "test me","Say \"Hello\"!","\\ \""
+```

9-regular-expressions/13-regexp-alternation/03-match-quoted-string/task.md

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+# Find quoted strings
+
+Create a regexp to find strings in double quotes `subject:"..."`.
+
+The strings should support escaping, the same way as JavaScript strings do. For instance, quotes can be inserted as `subject:\"` a newline as `subject:\n`, and the slash itself as `subject:\\`.
+
+```js
+let str = "Just like \"here\".";
+```
+
+Please note, in particular, that an escaped quote `subject:\"` does not end a string.
+
+So we should search from one quote to the other ignoring escaped quotes on the way.
+
+That's the essential part of the task, otherwise it would be trivial.
+
+Examples of strings to match:
+```js
+.. *!*"test me"*/!* ..  
+.. *!*"Say \"Hello\"!"*/!* ... (escaped quotes inside)
+.. *!*"\\"*/!* ..  (double slash inside)
+.. *!*"\\ \""*/!* ..  (double slash and an escaped quote inside)
+```
+
+In JavaScript we need to double the slashes to pass them right into the string, like this:
+
+```js run
+let str = ' .. "test me" .. "Say \\"Hello\\"!" .. "\\\\ \\"" .. ';
+
+// the in-memory string
+alert(str); //  .. "test me" .. "Say \"Hello\"!" .. "\\ \"" ..
+```