Question

iv 确实是一个简单的javascript问题。这里有一部分人用问话,但也有类似的方式通过javascript这样做。基本上,我写了几处文字,这样,当你点击一个具有价值的文本箱时,就算出你能够打出的数值(在大多数用户名箱中,他们在那里没有什么笔记)。这样做可能有更好的办法(我已经可以认为有些人),这样也能够自由提出。无论我从哪条手脚看,问题在于,如果用户再次点击所有数据,那么如果他们只是想调整他们可能掌握的东西,以解决这个问题(先在秘密显示代码),即设置一个核对变量,如果是的话。这是它所期望的。 (t t work, btw)

var unumber = 0;
var pnumber = 0; 

 if(unumber<1){
  $( #username ).click(function(){
  unumber = 1;
  $( #username ).val(  );
 });
 };

 if(pnumber<1){
   $( #password ).click(function(){
   $( #password ).val(  );
   pnumber = 1;
   });
 };

what I m assuming happens is that every time some one clicks the variables are reset, and this leads to a more general question if this is this case, why would the whole script, not just the event handler, run? Im new to javascript so forgive me if this is a stupid question. Anyways, this is a really simple script and there are better and more efficient ways to do it, but how can it be done this way?

Answer 1

不到1人的检查应在点击手里进行。

var unumber = 0;
var pnumber = 0; 

$( #username ).click(function(){
  if(unumber<1){
    unumber = 1;
    $( #username ).val(  );
  }
});

$( #password ).click(function(){
  if(pnumber<1){
     pnumber = 1;
     $( #password ).val(  );
  }
});

值得注意的是,这并不十分有力,它没有处理向田地标。处理<代码>focus活动。

Another problem is that you don t get the message back if you don t type anything and leave the field. A better approach is to compare against the initial value when the field receives focus. If there s nothing in there when you leave the field, restore to the original value.

http://github.com/mathiasbynens/jQuery-Plugin"。

此外,新的浏览器支持placeholder/code>。 http://www.paciellogroup.com/blog/02/html5-accessibility-chops-the-placeholder-attribute/

Answer 2

我这样说的最好办法是在案文投入中有一个明确的纽伦。 See here for an example : 我如何在像Pi”这样的超文本输入箱内放下一个明确 but子?

Answer 3

No need for the messy number checking, use data on the element in question

这应当为你工作。

$( #username,#password ).focus(function(){
  if(!$(this).data( seen )) {
    $(this).data( seen ,true);
    $(this).val(  );
  }
});

http://jsfiddle.net/DeZ7D/rel=“nofollow”> http://jsfiddle.net/DeZ7D/。

You could store the placeholder and replace back on blur if the user hasn t entered anything. more detailed implementation here:

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