Search code examples
javascriptregexcontrol-characters

Match non printable/non ascii characters and remove from text

My JavaScript is quite rusty so any help with this would be great. I have a requirement to detect non printable characters (control characters like SOH, BS etc) as well extended ascii characters such as Ž in a string and remove them but I am not sure how to write the code?

Can anyone point me in the right direction for how to go about this? This is what I have so far:

$(document).ready(function() {
    $('.jsTextArea').blur(function() {
        var pattern = /[^\000-\031]+/gi;
        var val = $(this).val();
        if (pattern.test(val)) {    
        for (var i = 0; i < val.length; i++) {
            var res = val.charAt([i]);
                alert("Character " + [i] + " " + res);              
        }          
    }
    else {
         alert("It failed");
     }

    });
});
Solution

  • To target characters that are not part of the printable basic ASCII range, you can use this simple regex:

    [^ -~]+

    Explanation: in the first 128 characters of the ASCII table, the printable range starts with the space character and ends with a tilde. These are the characters you want to keep. That range is expressed with [ -~], and the characters not in that range are expressed with [^ -~]. These are the ones we want to replace. Therefore:

    result = string.replace(/[^ -~]+/g, "");