Disable typing 0 (zero) at first character position

问题

I'm using a Jquery numeric plugin that only allows numeric values to be typed in an input

$("#tbQuan").numeric();

In addition to what this plugin is doing I need to disable typyng '0' (zero) at the first character position.

Any help would be appreciated.

回答1:

Try this.

$('input').keypress(function(e){ 
   if (this.value.length == 0 && e.which == 48 ){
      return false;
   }
});

Demo

回答2:

Something like this should get you started:

$("#tbQuan").numeric().keyup(function (e) {
    var val = $(this).val();
    while (val.substring(0, 1) === '0') {   //First character is a '0'.
        val = val.substring(1);             //Trim the leading '0'
    }
    $(this).val(val);   //update input with new value
});

回答3:

For the keyUp event

$('.numeric').keyup(function(event) {

var currentVal = $(this).val();

if (currentVal.length == 1 && (event.which == 48 || event.which == 96)) {
  currentVal = currentVal.slice(0, -1);
}
$(this).val(currentVal);

});

DEMO

make sure to add both 48 and 96 events to support number pad 0 and keyboard 0.
adding this way, user get to know that leading zeros are not allowed

回答4:

I'd start by trying something like this:

$('input').keyup(function(){ 
   if ( $(this).val().length === 1 && $(this).val() === 0 ){
      alert('No leading zeroes!');
   }
);

回答5:

if textbox in masked then:::

$('#numeric').keyup(function(event) {

    var currentVal = $(this).val();

    if (currentVal.substring(0, 1) === '0' && (event.which == 48 || event.which == 96)) {

      currentVal=currentVal.substring(1);
    }
    $(this).val(currentVal);
  });

OR *******************************

$("#numeric").keyup("input propertychange paste", function (e) {
var val = $(this).val()
var reg = /^0/gi;
if (val.match(reg)) {
    $(this).val(val.replace(reg, ""));
    alert("Please phone number first character bla blaa not 0!");
    $(this).mask("999 999-9999");

}

});

First Sample DEMO :

Second Sample DEMO :

来源：https://stackoverflow.com/questions/9106603/disable-typing-0-zero-at-first-character-position

标签

jquery

jquery-plugins