删除最后一个无效字符，而不是第一个（JavaScript验证）

Question

I am trying to write a javascript validation method so that, if more than one capital letter is entered, it removes the other capital letters on the fly. However, it is removing the first capital letter, and I want it to remove the last one (which doesn't exist at x=1 )

This is my code...

for(var x = 1, j = value.length; x < j; x++){
    if(value.charAt(x) != newValue.charAt(x)){
        valid = false;
        $("#text_10").attr({ 
            "value":$("#text_10").attr("value").replace(value.charAt(x), "")
         });
        finalVal = finalVal.replace(value.charAt(x), "");
    }
}

Is there any way to identify that last typed letter, without reversing the string, so that I can remove the capital letter?

Answer 1

反转您的字符串，然后通过“删除第一个大写字母”代码运行该字符串，然后将其重新反转。

Answer 2

You could use String.replace :

var one = false;
finalValue = value.replace(/([A-Z])/g, function () {
   if (one) return '';
   one = true;
   return arguments[1];
}); 

Answer 3

Reverse your loop index. Start at value.length and work your way back using x-- rather than x++ until you reach 0. You won't need j either at that point.

for (var i = value.length; i > 0; i--) {
    ...
}