Javascript提醒用户已经输入了相同的信息

Question

First I should say I am a javascript newbie so forgive my ignorance. 首先，我应该说我是一名JavaScript新手，所以请原谅我的无知。 I'm creating a form that has three functions and also uses array: Add - To accept a name (if field left blank it should ask the user to enter a name in an alert box) Find - To verify a name has not already been entered (in an alert box) List - To list the names that have been entered (in an alert box) 我正在创建具有三个功能并且还使用数组的表单：添加-接受名称（如果字段为空，则应要求用户在警报框中输入名称）查找-确认名称尚未被使用输入（在警报框中）列表-列出已输入的名称（在警报框中）

I have the list function working (good). 我有列表功能工作（好）。 The alert to enter a name comes up after you enter a name as well as when you leave the field blank (not good) and I can't get the find function to work at all. 输入名称后以及将字段保留为空白（不好）时，都会出现输入名称的警报，而我根本无法使用查找功能。 My code is below and I've tried so many iterations and searched so many sites for help, also tried firebug; 我的代码在下面，我尝试了许多迭代，并搜索了许多站点以寻求帮助，还尝试了Firebug。 I'm hoping someone can point me in the right direction. 我希望有人可以指出正确的方向。 Untitled 无标题

<body>
<script type="text/javascript">
  var a = new Array();

  function list() {
      var s = "";
      for (i = 0; i < a.length; i++)
          s = s + a[i] + "\n";
      alert(s);
  }

  function add() {
      // If the text box empty you ask the user to enter a name.
      var myTextField = document.getElementById("myText");
      a[a.length] = myTextField.value;
      myTextField.value = "";
      if (myTextField.value == "") {
          alert("Please enter a name");
          return false;
      }

      function find() {
          //If the name already exists you should get a warning
          var myTextField = document.getElementById("myText");
          a[a.length] = myTextField.value;
          myTextField.value = "";
          for (var i = 0; i < a.length; i++)
              if (a[i] == myTextField) {
                  alert("Sorry, the name " + a[i] + " already exists.  Try again");
              }
      }
  }

</script>
<input type="text" id="myText" /><br>
<input type="button" onclick="add()" value="Add a name" />
<input type="button" onclick="list()" value="List the names" />
<input type="button" onclick="find()" value="Find" />
</body>
</html>

Answer 1

The code had a couple of errors, here's a working version: http://jsfiddle.net/sAq2m/2/ 该代码有几个错误，这是一个有效的版本： http : //jsfiddle.net/sAq2m/2/

html: 的HTML：

<input type="text" id="myText" /><br>
<input type="button" onclick="add()" value="Add a name" />
<input type="button" onclick="listItems()" value="List the names" />
<input type="button" onclick="find()" value="Find" />

js: js：

 var a = [];
  function listItems()
 {
  var s = "";
  for(var i = 0; i < a.length; i++)
  s = s + a[i] + "\n";
  alert(s);
     return false;
 }

 function add()
{
   // If the text box empty you ask the user to enter a name.
 var myTextField = document.getElementById("myText");
    var v = myTextField.value
    if (!v){
        v = prompt("You have not entered a name, please enter one.");
    } 
    a.push(v);

    console.log(a);
  myTextField.value = "";      

 return false;
}
 function find()
{
 //If the name already exists you should get a warning
 var myTextField = document.getElementById("myText");

 for (var i = 0; i < a.length; i++)
    if (a[i] == myTextField.value)
    { 
        alert ("Sorry, the name " + a[i] + " already exists.  Try again");
        return;
    }
}

Answer 2

You have done it almost, but some lil errors.. here you can check it jsfiddle 您已经差不多完成了，但是有些小错误。在这里您可以检查它jsfiddle

HTML: HTML：

<input type="text" id="myText" /><br>
<input type="button" value="Add a name" class="add_button"/>
<input type="button" value="List the names" class="list_button"/>
<input type="button" value="Find" class="find_button"/>

JS: JS：

$(".add_button").live("click", function(){
    add()
});

$(".list_button").live("click", function(){
    list()
});

$(".find_button").live("click", function(){
    find()
});


var a = new Array();
function list()
{
    var s = "";
    for(i = 0; i < a.length; i++)
    s = s + a[i] + "\n";
    alert(s);
 }

function add()
{
   // If the text box empty you ask the user to enter a name.
    var myTextField = document.getElementById("myText");
    a[a.length] = myTextField.value;

    if (myTextField.value == "")
    {
        alert ("Please enter a name");
        return false;
    }
    myTextField.value = "";
}

function find()
{
    //If the name already exists you should get a warning
    var status = true;
    var myTextField = document.getElementById("myText");

    for (var i = 0; i < a.length; i++)
    {
        if (a[i] == myTextField.value)
        {
            alert ("Sorry, the name " + a[i] + " already exists.  Try again");
            status = false;
            break;
        }
    }
    if(status==true)
    {
        a[a.length] = myTextField.value;
    }
    myTextField.value = "";
}

Javascript提醒用户已经输入了相同的信息

问题描述

2 个解决方案

解决方案1
0 2013-11-02 19:04:31

解决方案2
0 已采纳 2013-11-02 19:30:27

Javascript提醒用户已经输入了相同的信息

问题描述

2 个解决方案

解决方案1 0 2013-11-02 19:04:31

解决方案2 0 已采纳 2013-11-02 19:30:27

解决方案1
0 2013-11-02 19:04:31

解决方案2
0 已采纳 2013-11-02 19:30:27