实例 该实例演示了 defaultValue 和 value 属性的区别: var x = document.getElementById("myEmail");var defaultVal = x.defaultValue;var currentVal = x.value; 尝试一下 » Input Email 对象 <input> - datetime-local HTML DOM FileUploa
1.可以用简单的方式,就是给input文本框加上onfocus属性,如下代码: <input id="keyword" name="keyword" size="10" class="inputstyle keywords" value="请输入关键字进行搜索" onfocus='if(this.value=="请输入关键字进行搜索"){this.value="";}; ' onblur='if(this.value==""){this.value="请输入...
❮ Input Text Object Example Change the default value of a text field: document.getElementById("myText").defaultValue="Goofy"; Try it Yourself » Description The defaultValue property sets or returns the default value of a text field. ...
oInput.onblur=function(){ if(!oInput.value){ oInput.value=oInput.defaultValue; this.style.color='#999'; }; }; }; </script> </head> <body> <a href="###">输入框提示文字灰色效果</a>, <input type="text" id="input1" name="lee" value="请输入关键词" style="color:#999999">...
Example An example that shows the difference between the defaultValue and value property: var x = document.getElementById("myRange");var defaultVal = x.defaultValue;var currentVal = x.value; Try it Yourself » ❮ Input Range Object ...
onblur='if(this.value==""){this.value="请输入关键字进行搜索";}; this.className="input02"'> 2.也可以使用jquery实现: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 $(document).ready(function() { var vdefault = $('#keyword').val(); ...
alertDefaultValue() { alert(document.getElementById('txt1').defaultValue); } </script> </head> <body> <textarea id="txt1"> Hello world...This is a text area </textarea> <br /> <input type="button" onclick="alertDefaultValue()" value="Alert default value" /> </body> </html>...
<input name=”emaill" type= " email" value=fning@ /> 1. (3)placeholder属性 placeholder是指当 文本框处于末输入状态时文本框中显示的输入提示。在输入框为空时显式出现,而当输入框获得焦点时则会消失。 例如: < input type="text" placeholder = "default text" /> ...
</p><p><input type="text"id="return_value"value=""placeholder="请输入内容"/></p><button id="close">关闭对话框</button></dialog><button id="show">显示对话框</button><!--script--><script>vardialog=document.querySelector("dialog");document.querySelector("#show").onclick=function(...
<input type="number" max="100" min="10" value=""> 方式二：oninput // 只限制长度：输入...