Question

Let’s say that I have like this: "\\n", I need to convert it to a string like if the interpreter would do it: \n.

A simple replace like this wouldn’t work:

function aaa(s){
    return s.replace(/\\n/gm,'\n').replace(/\\\\/gm,'\\');
}

---

I need this behaviour:

• "Line 1\nLine 2" => Line 1<Line break>Line 2
• "Line 1\\nLine 1" => Line 1\nLine1

Answer 1

The simplest, and most evil, solution, is to write return eval(s).
Do not do that.

Instead, you need to make a single replace call with a match evaluator, like this:

var escapeCodes = { 
    '\\': '\\',
    'r':  '\r',
    'n':  '\n',
    't':  '\t'
};

return s.replace(/\\(.)/g, function(str, char) {
    return escapeCodes[char];
});

(Tested)