[javascript] Escaping single quotes in JavaScript string for JavaScript evaluation

I have a project, in which some JavaScript var is evaluated. Because the string needs to be escaped (single quotes only), I have written the exact same code in a test function. I have the following bit of pretty simple JavaScript code:

function testEscape() {
    var strResult = "";
    var strInputString = "fsdsd'4565sd";

    // Here, the string needs to be escaped for single quotes for the eval 
    // to work as is. The following does NOT work! Help!
    strInputString.replace(/'/g, "''");

    var strTest = "strResult = '" + strInputString + "';";
    eval(strTest);
    alert(strResult);
}

And I want to alert it, saying: fsdsd'4565sd.

Best to use JSON.stringify() to cover all your bases, like backslashes and other special characters. Here's your original function with that in place instead of modifying strInputString:

function testEscape() {
    var strResult = "";
    var strInputString = "fsdsd'4565sd";

    var strTest = "strResult = " + JSON.stringify(strInputString) + ";";
    eval(strTest);
    alert(strResult);
}

(This way your strInputString could be something like \\\'\"'"''\\abc'\ and it will still work fine.)

Note that it adds its own surrounding double-quotes, so you don't need to include single quotes anymore.

I agree that this var formattedString = string.replace(/'/g, "\\'"); works very well, but since I used this part of code in PHP with the framework Prado (you can register the js script in a PHP class) I needed this sample working inside double quotes.

The solution that worked for me is that you need to put three \ and escape the double quotes. "var string = \"l'avancement\"; var formattedString = string.replace(/'/g, \"\\\'\");"

I answer that question since I had trouble finding that three \ was the work around.

var str ="fsdsd'4565sd"; str.replace(/'/g,"'")

This worked for me. Kindly try this

That worked for me.

string address=senderAddress.Replace("'", "\\'");

strInputString = strInputString.replace(/'/g, "''");

Only this worked for me:

searchKeyword.replace(/'/g, "\\\'");//searchKeyword contains "d'av"

So, the result variable will contain "d\'av".

I don't know why with the RegEx didn't work, maybe because of the JS framework that I'm using (Backbone.js)

There are two ways to escaping the single quote in JavaScript.

1- Use double-quote or backticks to enclose the string.

Example: "fsdsd'4565sd" or `fsdsd'4565sd`.

2- Use backslash before any special character, In our case is the single quote

Example:strInputString = strInputString.replace(/ ' /g, " \\' ");

Note: use a double backslash.

Both methods work for me.