Javascript - Replacing the escape character in a string literal

Question

I am trying to replace the backslash (escape) character in a Javascript string literal.

I need to replace it with a double backslash so that I can then do a redirec

Answer 1

To better demonstrate and understand the string-escaping behavior, take the following example:

You can see what the string looks like in memory after being parsed by the JS-engine by splitting the string, thus also offering potential (ugly) solutions around this issue:

'file:///C:\funstuff\buildtools\viewer.html'.split('')
//>
 ["f", "i", "l", "e", ":", "/", "/", "/", "C", ":", "", "u", "n", "s", "t", "u",
  "f", "f", "", "u", "i", "l", "d", "t", "o", "o", "l", "s", "", "i", "e", "w",
  "e", "r", ".", "h", "t", "m", "l"]

'file:///C:\funstuff\buildtools\viewer.html'.split('').map( function(e){
     return e.charCodeAt()
});
//>
[102, 105, 108, 101, 58, 47, 47, 47, 67, 58, 12, 117, 110, 115, 116, 117, 102,
 102, 8, 117, 105, 108, 100, 116, 111, 111, 108, 115, 11, 105, 101, 119, 101, 
 114, 46, 104, 116, 109, 108]
//>in Hex values by applying .toString(16)
["66", "69", "6c", "65", "3a", "2f", "2f", "2f", "43", "3a", "c", "75", "6e", 
 "73", "74", "75", "66", "66", "8", "75", "69", "6c", "64", "74", "6f", "6f", 
 "6c", "73", "b", "69", "65", "77", "65", "72", "2e", "68", "74", "6d", "6c"]

Basically the single backslash escapes the following character, thus giving rise to unexpected results, if the escaping-context is not heeded.

Solution:

Through a look-up-table, you can restore many errantly escaped characters if they lie outside the printable ASCII character range of \x20-\x7F. For the example above for instance, 12 or \x0c [ 12..toString(16) ] would become '\\'+'v', and so on.

PS: Be aware that a loss of information occured, and you are trying to restore information through contextual- or meta- information, meaning in your case that the string is in the printable ASCII range.

Please share any implementations with the community. Cheers!