javascript code to check special characters and add double slash before that?

问题

My string contains some of the special characters that needs to be escaped with (\) double backslash before the string. My piece of code below:

var data = "abckdef)ghijkl)-8-mno-3-(pqrstuvw-1-xyz)-5-thiaa-1-aza-";
var iChars = "!@#$%^&*()+=-[]\\\';,./{}|\":<>?~_";
for (var i = 0; i < data.length; i++) {
    if (iChars.indexOf(data.charAt(i)) != -1) {
        console.log("Your string has special characters. \nThese are not allowed.");
        return false;
    }
}

Expected Result would be:

abckdef\)ghijkl\)\-8\-mno\-3\-\(pqrstuvw\-1\-xyz\)\-5\-thiaa\-1\-aza\-

Above code finds the special characters in my string, but I wanted to add (\\) before every occurrences of the special characters. Any help on this?

回答1:

Use a regex replacement:

Match:

/[!@#$%^&*()+=\-[\]\\';,./{}|":<>?~_]/

Replace to:

\$&

>>> data.replace(/[!@#$%^&*()+=\-[\]\\';,./{}|":<>?~_]/g, "\\$&")
... "abckdef\)ghijkl\)\-8\-mno\-3\-\(pqrstuvw\-1\-xyz\)\-5\-thiaa\-1\-aza\-"

回答2:

Regex:

([!@#$%^&*()+=\[\]\\';,./{}|":<>?~_-])

Replacement string:

\$1

DEMO

> var data = "abckdef)ghijkl)-8-mno-3-(pqrstuvw-1-xyz)-5-thiaa-1-aza-";
undefined
> var result = data.replace(/([!@#$%^&*()+=\[\]\\';,./{}|":<>?~_-])/g, "\\$1");
undefined
> console.log(result);
abckdef\)ghijkl\)\-8\-mno\-3\-\(pqrstuvw\-1\-xyz\)\-5\-thiaa\-1\-aza\-

回答3:

Try this plug and play function.

var data = "abckdef)ghijkl)-8-mno-3-(pqrstuvw-1-xyz)-5-thiaa-1-aza-";

function escapeSpecialCaseChar(text) {
   return text.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, '\\$&');
}

console.log(escapeSpecialCaseChar(data));

回答4:

Do you want to escape anything other than alphanumeric character then make it simple

Find what :([^a-zA-Z0-9]) Replacement: \\$1

regex101 demo

Sample code:

var re = /([^a-zA-Z0-9])/g; 
var str = 'abckdef)ghijkl)-8-mno-3-(pqrstuvw-1-xyz)-5-thiaa-1-aza-';
var subst = '\\$1'; 

var result = str.replace(re, subst);

output: (same as expected)

abckdef\)ghijkl\)\-8\-mno\-3\-\(pqrstuvw\-1\-xyz\)\-5\-thiaa\-1\-aza\-

来源：https://stackoverflow.com/questions/25376698/javascript-code-to-check-special-characters-and-add-double-slash-before-that

标签

javascript

regex

special-characters