我如何让我的正则表达式用附加变量将小写字母替换为大写字母

Question

I have an app that in the UK POSTCODE i want the client to type in their postcode and several things happen... 1) i only allows AZ and 0-9 2) only space is allowed as special character

Im getting what i want except that it allows upper and lowercase

I know that the /i allows any case so please dont point this out. If i remove it and the client types in for example "sw10 9ef" they are not paying attention to whats being typed in and were getting "10 9" for customers who use lowercase but correct who uses uppercase "SW10 9EF"

Any help would be appreciated

Lee

<script>
function postOnly(input) {
    var regex = /[^0-9A-Z ]/gi;
    input.value = input.value.replace(regex, "");
}
</script>




<div class="form-group">
        <label class="col-sm-12 col-md-12 col-lg-12 control-label"><i class="fas fa-map-marked-alt fa-lg"></i> Postal Code ( ZZZZ XXX or ZZZ XXX ) 
</label>
        <div class="col-sm-12 col-md-12 col-lg-12">
            <input type="text" value="<?php echo set_value('postal_code'); ?>" name="postal_code" onkeyup="postOnly(this)" class="form-control" placeholder="Postal Code ( ZZZZ XXX or ZZZ XXX )">
            <br>
        </div>
    </div>

So i need it to change the case from lower to upper live whilst keeping the above requirements.

Answer 1

You really shouldn't be using the front end of your application to add restrictions to the incoming data, or at least not only the front end, as it's trivial to bypass. Taking that on board your front end should really not care weather or not a user is using upper or lower case letters in a postcode and the back end should convert lower case letters to upper case ones before further processing.

You can add a text-transform:uppercase style to the input box so that what ever the user types appears to be in upper case, but that is only a visual styling and if the user inputs the postcode in lower case then it will be returned to the back end application as lower case letters.

Answer 2

You should check:

1. Your regex allow both uppercase and lowercase characters.

2. After checking that your input value is correct as per your requirements convert your input value to upper case.

    var regex=/[^0-9A-Za-z ]/g; if(input.value.match(regex)){ input.value=input.value.toUpperCase(); }