如何将多个ID简化为多个功能？

Question

我有以下检查日期输入的代码。我希望用户键入 dd/MM/YYYY。如果用户输入 dd/MM/YY，我会提醒他们。我正在为每个输入标签编写每个 javascript 函数。如何简化 javascript 函数或者我不能？

<input id="dt_join" name="dt_join" value="<%=dt_join%>" type="text" class="form-control" date-picker onblur="checkdt_join();">

<input id="dt_confirm" name="dt_confirm" value="<%=dt_confirm%>" type="text" class="form-control" datewotoday onblur="checkdt_confirm();">

<input id="dt_resign" name="dt_resign" value="<%=dt_resign%>" type="text" class="form-control" datewotoday onblur="checkdt_resign();">

function checkdt_join(){
    var input = document.getElementById("dt_join").value;
    var pattern =/^([0-9]{1,2})\/([0-9]{1,2})\/([0-9]{4})$/;

    if (pattern.test(input)==false){
        alert("Date format is incorrect, please key in DD/MM/YYYY");
        }   
    }

function checkdt_confirm(){
    var input = document.getElementById("dt_confirm").value;
    var pattern =/^([0-9]{1,2})\/([0-9]{1,2})\/([0-9]{4})$/;

    if (pattern.test(input)==false){
        alert("Date format is incorrect, please key in DD/MM/YYYY");
        }   
    }
function checkdt_resign(){
    var input = document.getElementById("dt_resign").value;
    var pattern =/^([0-9]{1,2})\/([0-9]{1,2})\/([0-9]{4})$/;

    if (pattern.test(input)==false){
        alert("Date format is incorrect, please key in DD/MM/YYYY");
        }   
    }

Answer 1

简单而肮脏的方法：通过 onblur 属性中的 this 传递输入元素。（删除了与问题无关的属性）

function checkdt(el) {
  var input = el.value;
  var pattern = /^(\d{1,2})\/(\d{1,2})\/(\d{4})$/;

  if (pattern.test(input) == false) {
    alert("Date format is incorrect, please key in DD/MM/YYYY");
  }
}

<input value="01/01/2001" type="text" onblur="checkdt(this);" />
<input value="11/11/2011" type="text" onblur="checkdt(this);" />
<input value="12/12/2012" type="text" onblur="checkdt(this);" />

明确一则：使用事件监听器

$(function() {
  $(".date-checker").blur(function checkdt() {
    var input = this.value;
    var pattern = /^([0-9]{1,2})\/([0-9]{1,2})\/([0-9]{4})$/;

    if (pattern.test(input) == false) {
      alert("Date format is incorrect, please key in DD/MM/YYYY");
    }
  });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input value="01/01/2001" class="date-checker" type="text" />
<input value="11/11/2011" class="date-checker" type="text" />
<input value="12/12/2012" class="date-checker" type="text" />

如何将多个ID简化为多个功能？

How to simplify multiple IDs to multiple function?

javascript

datepicker

asp-classic