javascript 获取表单元素的几种方法

<code class="language-javascript">document.pref.color.value;//pref表示form表单的name,color是表单中元素的名称。</code>

<code class="language-html">

    <script language="JavaScript">
    function showColor(){
      var color = document.pref.color.value;
      console.log("Your favorite color is: " + color);
    }
    </script><form name="pref" method="POST">
    Enter the name of your favorite car:
      <input type="text" name="car" size="25"><input id="button1" type="BUTTON" name="carButton" value="Show Car" onclick="showCar(this.form)"><br>
    Enter your favorite color:
      <input type="text" name="color" size="15"><input type="BUTTON" name="colorButton" value="Show Color" onclick="showColor(this.form)">
</form>

</code>

<code class="language-javascript">document.pref.elements[0].value //表示name为pref表单中第一个元素的值</code>

<code class="language-html">

    <script language="JavaScript">
    function showCar(){
      var car = document.pref.elements[0].value;
      console.log("Your favorite car is: " + car);
    }
    </script><form name="pref" method="POST">
    Enter the name of your favorite car:
      <input type="text" name="car" size="25"><input id="button1" type="BUTTON" name="carButton" value="Show Car" onclick="showCar(this.form)"><br>
    Enter your favorite color:
      <input type="text" name="color" size="15"><input type="BUTTON" name="colorButton" value="Show Color" onclick="showColor(this.form)">
</form>

</code>

<code class="language-javascript">document.getElementById("id").value;</code>

<code class="language-html">
    
    <script language="JavaScript">
    function getName(){
         var textName = document.getElementById("text_id").value;
         console.log("The textbox name is: " + textName);
    }
    </script><form name="form1">
    This is a blank input textbox. Click on the button below to get the name of the textbox.
    <br><input type="text" id="text_id" name="textbox1" size="25"><br><br><input type="button" value="Get Name" onclick="getName()">
</form>
    
</code>