放置任何值,当重复单击减少/减少时,输入框文本将突出显示哪个不是我想要发生的.

我试过用户选择：无但仍然没有任何效果.

$(".increment").click(function() {
   var score1 = $(".score").val();
   score1++;
   $(".score").val(score1);
 });

 $(".decrement").click(function() {
   var score1 = $(".score").val();
   if (score1 == 0) {} else {
     score1--;
     $(".score").val(score1);
   }
 });

 $(function() {
   $('input').bind('focus',false);
 });

body {
  margin: 20px;
}

input[type=number]::-webkit-inner-spin-button,input[type=number]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.prdin {
  text-align: center;
  background: #f5f5f5;
  width: 40px;
  border: 1px solid #ccc;
  border-top: 0px;
  margin: 20px;
}

.prdin div {
  display: flex;
  height: 37px;
  justify-content: center;
  align-items: center;
  border-top: 1px solid #ccc;
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  -khtml-user-select: none;
  -moz-user-select: none -ms-user-select: none;
  user-select: none;
}

.prdin input {
  text-align: center;
  border: 0px;
  height: 100%;
  width: 100%;
  font-size: 18px;
  font-weight: bold;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>

<!-- For icon styles -->
<link href="https://cdnjs.cloudflare.com/ajax/libs/simple-line-icons/2.4.1/css/simple-line-icons.css" rel="stylesheet" />

<div class="prdin">
  <div class="increment">
    <i class="icon-arrow-up icons"></i>
  </div>
  <div id="input1">
    <input type="number" class="score" value="0">
  </div>
  <div class="decrement">
    <i class="icon-arrow-down icons"></i>
  </div>
</div>

<div class="prdin">
  <div class="increment">
    <i class="icon-arrow-up icons"></i>
  </div>
  <div id="input1">
    <input type="number" class="score" value="0">
  </div>
  <div class="decrement">
    <i class="icon-arrow-down icons"></i>
  </div>
</div>