javascript清除字段值输入

Question

I am making a simple form and i have this code to clear the initial value:

Javascript:

function clearField(input) {
    input.value = "";
};

html:

<input name="name" id="name" type="text" value="Name" onfocus="clearField(this);"/>

But what i don't want is that if the user fills the input but clicks it again, it gets erased. I want the field to have the starter value "Name" only if the input is empty. Thank you in advance!

Answer 1

do like

<input name="name" id="name" type="text" value="Name" 
   onblur="fillField(this,'Name');" onfocus="clearField(this,'Name');"/>

and js

function fillField(input,val) {
      if(input.value == "")
         input.value=val;
};

function clearField(input,val) {
      if(input.value == val)
         input.value="";
};

update

here is a demo fiddle of the same

Answer 2

Here is one solution with jQuery for browsers that don't support the placeholder attribute.

$('[placeholder]').focus(function() {
  var input = $(this);

  if (input.val() == input.attr('placeholder')) {
    input.val('');
    input.removeClass('placeholder');
  }
}).blur(function() {
  var input = $(this);

  if (input.val() == '' || input.val() == input.attr('placeholder')) {
    input.addClass('placeholder');
    input.val(input.attr('placeholder'));
  }
}).blur();

Found here: http://www.hagenburger.net/BLOG/HTML5-Input-Placeholder-Fix-With-jQuery.html

Answer 3

This may be what you want:

Working jsFiddle here

• This code places a default text string Enter your name here inside the <input> textbox, and colorizes the text to light grey.

• As soon as the box is clicked, the default text is cleared and text color set to black.

• If text is erased, the default text string is replaced and light grey color reset.

---

HTML:

<input id="fname" type="text" />

jQuery/javascript:

$(document).ready(function() {

    var curval;
    var fn = $('#fname');
    fn.val('Enter your name here').css({"color":"lightgrey"});

    fn.focus(function() {
        //Upon ENTERING the field
        curval = $(this).val();
        if (curval == 'Enter your name here' || curval == '') {
            $(this).val('');
            $(this).css({"color":"black"});
        }
    }); //END focus()

    fn.blur(function() {
        //Upon LEAVING the field
        curval = $(this).val();
        if (curval != 'Enter your name here' && curval != '') {
            $(this).css({"color":"black"});
        }else{
            fn.val('Enter your name here').css({"color":"lightgrey"});
        }
    }); //END blur()

}); //END document.ready

Answer 4

HTML:

<input name="name" id="name" type="text" value="Name" onfocus="clearField(this);" onblur="fillField(this);"/>

JS:

function clearField(input) {
  if(input.value=="Name") { //Only clear if value is "Name"
    input.value = "";
  }
}
function fillField(input) {
    if(input.value=="") {
        input.value = "Name";
    }
}

Answer 5

 var input= $(this);    
 input.innerHTML = '';