How do I remove the last character in some text being copied from one field to another using JavaScr-CodePudding

I have a form that I created to make my work easier and recently figured out how to make certain fields automatically generate a comma and separates after 5 letters or numbers have been typed into it (CPT codes for medical claims that I have to look up) using the same coding you would for putting spaces between numbers. I also have coding here that would force letters to be capitalized since I'm a bit OCD about that stuff for work:

<input name="checkbox24" type="checkbox" id="checkbox24" onClick="FillDetails24(this.form);" /><span style="background-color:yellow">CPT</span>
 <input type = "text" size="8" class = "uc-text-smooth" name="textfield24" id="textfield24" />

<script language = "JavaScript">
const forceKeyPressUppercase = (e) => {
 let el = e.target;
 let charInput = e.keyCode;
 if((charInput >=97) && (charInput <= 122)) { // lowercase
   if(!e.ctrlKey && !e.metaKey && !e.altKey) { // no modifier key
     let newChar = charInput - 32;
     let start = el.selectionStart;
     let end = el.selectionEnd;
     el.value = el.value.substring(0, start)   String.fromCharCode(newChar)   el.value.substring(end);
     el.setSelectionRange(start 1, start 1);
     e.preventDefault();
    }
  }
};

document.querySelectorAll(".uc-text-smooth").forEach(function(current) {
  current.addEventListener("keypress", forceKeyPressUppercase);
});


        document.getElementById('textfield24').addEventListener('input', function (g) {
  g.target.value = g.target.value.replace(/[^\dA-Z]/g, '').replace(/(.{5})/g, '$1, ').trim();
});
</script>

When I use the checkbox, it automatically generates pre-written text using the following JavaScript:

function FillDetails24(f) {
  const elem = f.Reason;
  const x = f.Action;
  const y = f.Resolution;
     f.Reason.value  = ("Verify CPT "   f.textfield24.value   ". "   '\n');
     f.Action.value  = ("Adv on how to locate and use CPT lookup tool on plan website. Information provided in resolution. "   '\n');
 f.Resolution.value  = ("Adv on how to locate and use CPT lookup tool on plan website. Caller is looking to verify CPT "   f.textfield24.value   ". "   '\n'   '\n' );

}

However, because of the way that I put it together, the end result would be, "Adv on how to locate and use CPT lookup tool on plan website. Caller is looking to verify CPT V2020, 99213,. " The extra comma at the end is driving me nuts.

Since it was my first time using this

        document.getElementById('textfield24').addEventListener('input', function (g) {
  g.target.value = g.target.value.replace(/[^\dA-Z]/g, '').replace(/(.{5})/g, '$1, ').trim();
});

with this

function FillDetails24(f) {
  const elem = f.Reason;
  const x = f.Action;
  const y = f.Resolution;
     f.Reason.value  = ("Verify CPT "   f.textfield24.value   ". "   '\n');
     f.Action.value  = ("Adv on how to locate and use CPT lookup tool on plan website. Information provided in resolution. "   '\n');
 f.Resolution.value  = ("Adv on how to locate and use CPT lookup tool on plan website. Caller is looking to verify CPT "   f.textfield24.value   ". "   '\n'   '\n' );

}

I'm not certain how I can code it to eliminate the last comma generated at the end when it pulls the value of textfield24.

This is a very long, complex html form I've coded by hand for fun and for personal use at work for 4 years with only a couple years of HTML training and a little bit of JavaScript I learned in high school forever ago and I've been busting my butt to make this work perfectly so that I only have to tweak the pre-written stuff when things change at work.

I'm at a loss on how to continue. Any suggestions?

CodePudding user response：

you can use substring to remove the last comma, but you have to make sure that the last comma always be there. otherwise, you're gonna remove something else.

const example = "Adv on how to locate and use CPT lookup tool on plan website. Caller is looking to verify CPT V2020, 99213,. ";

const result = example.substring(0, example.lastIndexOf(","))   ".";

console.log(result);

CodePudding user response：

You can replace with regex /,$/.

f = { textfield24: { value: 'V2020, 99213,'} }
console.log(f.textfield24.value);
console.log(f.textfield24.value.replace(/,$/, ''));

function FillDetails24(f) {
  const elem = f.Reason;
  const x = f.Action;
  const y = f.Resolution;
     f.Reason.value  = ("Verify CPT "   f.textfield24.value   ". "   '\n');
     f.Action.value  = ("Adv on how to locate and use CPT lookup tool on plan website. Information provided in resolution. "   '\n');
 f.Resolution.value  = ("Adv on how to locate and use CPT lookup tool on plan website. Caller is looking to verify CPT "   f.textfield24.value.replace(/,$/, '')   ". "   '\n'   '\n' );

}