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How to operate JS to realize placeholder attribute prompt text in html

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Jun 02, 2018 pm 04:01 PM

htmljavascriptplaceholder

This time I will show you how to operate JS to realize the placeholder attribute prompt text in html. What are the precautions for using JS to implement the placeholder attribute prompt text in html. The following is a practical case. Let’s take a look. .

How to realize the placeholder attribute effect of html through js

We need to do this:

nbsp;html>

  
    <meta>
    <title>JS实现placeholder属性效果</title>
    <script>
      function bl(){
        var a=document.getElementById("inpt");
        if(a.value.length<=0){
          a.style.color="#999999";
          a.value="请输入姓名";
        }
      }
      function fo(){
        var a=document.getElementById("inpt");
        if(a.value=="请输入姓名"){
          a.style.color="black";
          a.value="";
        }
      }
    </script>
  
  
    <input>

The operation effect is as follows:

Supplement:

Here is another example of the placeholder attribute effect implemented by jQuery:

nbsp;html>


<meta>
<title>www.jb51.net jQuery实现placeholder属性效果</title>
<script></script>


<input>
<script>
function placeHolder(event){
 var self = $(this), selfDataValue = self.attr("data-value"), selfValue = self.val();
 if(selfDataValue){
  event.type == "click" ? (selfValue == selfDataValue && (self.val("").css("color","#333"))) : (event.type == "blur" && (selfValue == "" && (self.val(selfDataValue).css("color","#A9A9A9"))))
 }else{
  return false;
 }
}
$("#inpt").on("click blur",placeHolder);
</script>

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

Recommended reading:

How to use Vue to write a two-way data binding

How to use Vue to implement a countdown button

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