Stripping Special Characters from Strings in JavaScript without Regex

strip_special_chars.js

/*
Last night while working on my latest project, a personal finance application, 
I ran across the need to strip certain (special) characters from a string of 
user input in JavaScript. I assumed that there was an easy built in feature to 
do this in JavaScript, but most of the examples I found either used Regex which 
I don’t really want to use, or utilized some other confusing method that was 
not particularly straight forward. So, I decided to go ahead and post my ugly 
yet simple solution here on the blog in case anyone else might one day need it.

For my technique, I simply have one string variable that I want to strip special 
characters from, and another empty string which I will append characters from 
the original string excluding any special characters that I want to ‘strip’:
*/

var dollars = prompt("Enter a dollar value with or without $ and . characters:");
var dollarsClean = "";

var isNumberOrDecimal = false;
// loop through characters and build new string
for (var i = 0; i < dollars.length; i++) {
    // check for desired characters
    if (dollars.substr(i, 1) === '0') {
        isNumberOrDecimal = true;
    } else if (dollars.substr(i, 1) === '1') {
        isNumberOrDecimal = true;
    } else if (dollars.substr(i, 1) === '2') {
        isNumberOrDecimal = true;
    } else if (dollars.substr(i, 1) === '3') {
        isNumberOrDecimal = true;
    } else if (dollars.substr(i, 1) === '4') {
        isNumberOrDecimal = true;
    } else if (dollars.substr(i, 1) === '5') {
        isNumberOrDecimal = true;
    } else if (dollars.substr(i, 1) === '6') {
        isNumberOrDecimal = true;
    } else if (dollars.substr(i, 1) === '7') {
        isNumberOrDecimal = true;
    } else if (dollars.substr(i, 1) === '8') {
        isNumberOrDecimal = true;
    } else if (dollars.substr(i, 1) === '9') {
        isNumberOrDecimal = true;
    } else if (dollars.substr(i, 1) === '.') {
        isNumberOrDecimal = true;
    }

    if (isNumberOrDecimal) {
        dollarsClean += dollars.substr(i, 1);
    }

    // set variable back to false for next iteration of the loop
    isNumberOrDecimal = false;
}

alert(dollarsClean);