Got stumped by this for ages and all the answers kept insisting that the source string needs to already have escaped backslashes in it ... which isn't always the case.

Do this ..

var replaced = str.replace(String.fromCharCode(92),String.fromCharCode(92,92));

You've said what you quoted above is a string, but it's unclear whether you mean this (shortened a bit):

var str = "<tr><td><span class=\'label label-info\'>Dialed...";

...where what you've quoted is what you literally have within quotes, or this (note the backslashes):

var str = "<tr><td><span class=\\'label label-info\\'>Dialed...";

...where what you've quoted is the actual content of the string, not part of a string literal.

The first one above doesn't have any backslashes in it, it has escaped ' characters. The second one has backslashes in it.

To remove the backslahes from the second one:

str = str.replace(/\\/g, "");

When you give a regular expression with the g flag to replace, it applies globally throughout the string. Backslashes have special meaning in regular expressions, and so I've had to escape the backslash (with another backslash, it's the escape character for regular expressions as well as strings). So in the above, I'm saying to replace all backslashes with an empty string.

Try

str = str.replace(/\\/g, '');

Andrew Cooper's answer is correct in terms of why that third statement is going wrong. But you're also overwriting newbigbend each time, so you won't see the result of the first two replacements at all.

If you're trying to replace all slashes, backslashes, and asterisks with nothing, do this:

newbigbend = bb_val.replace(/[/\\*]/g, "");

Note you don't need the i flag, none of those characters is case sensitive anyway. (And note that within the [], you don't need to escape / or *, because they don't have special meaning there.) Live example.

But if you want it as three individual statements for whatever reason, then use newbigbend in the second two (and add the backslash Andrew flagged up):

newbigbend = bb_val.replace(/\//gi,"");
newbigbend = newbigbend.replace(/\\/gi,"");
newbigbend = newbigbend.replace(/\*/gi,"");

You don't need to make a regex a string, and it helps having that first / in there

Path = Path.replace(/\\/g, "|")

Actually, the first method is correct and works. Two backslash is indeed used to make a single backslash.

console.log("hello & 100%".replace(/([&%$#_{}])/g, "\\$1")); // "hello \& 100\%"

If console.log is giving you some trouble, which it shouldn't, try alert. Also you need to use the return value which you aren't doing.