Geek asks and answers

How to avoid and avoid quotation marks in JavaScript?

Here is a short piece of code:

var utility = {
    escapeQuotes: function(string) {
        return string.replace(new RegExp('"', 'g'),'\\"');
    },
    unescapeQuotes: function(string) {
        return string.replace(new RegExp('\\"', 'g'),'"');
    }
};

var a = 'hi "';

var b = utility.escapeQuotes(a);
var c = utility.unescapeQuotes(b);

console.log(b + ' | ' + c);

I expect this code to work, but as a result, I get:

hi \" | hi \"

If I change the first parameter of the new RegExp constructor in the unescapeQuotes method to 4 backslashes, everything starts working as it should.

string.replace(new RegExp('\\\\"', 'g'),'"');

Result:

hi \" | hi "

Why are four backslashes required as the first parameter of the new RegExp constructor? Why doesn't he work with only two of them?

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1 answer

The problem is that you are using a constructor RegExpthat takes a string, and not using a regular expression literal. So, on this line in your unescape:

return string.replace(new RegExp('\\"', 'g'),'"');

... \\ JavaScript , . , , , \". - escape , \" ". , ; , ( ).

RegExp (, - ), :

var utility = {
    escapeQuotes: function(string) {
        return string.replace(/"/g, '\\"');
    },
    unescapeQuotes: function(string) {
        return string.replace(/\\"/g, '"');
    }
};

.

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