如何根据条件在输入文本下发出警报?

时间:2017-04-29 06:39:52

标签: javascript php validation input alert

Please look the picture here

enter image description here

想分开警报。因此,当值为空或为空时,警报 nama pengguna必须输入。如果值小于5,则警报最少5个字符

因为风格只是喜欢它(红色文字,在输入文字下)。我的意思是不使用javascript警报。

这是我的代码:



function checkLength() {
	var textbox = document.getElementById("username");
	if(textbox.value.length <= 5) {
		alert("min 5 characters");
	}
	else if(textbox.value.length == 0){
		alert("nama pengguna must inputed")
	}
}
&#13;
<div class="form-group required2">
	<label class="control-label visible-ie8 visible-ie9">Nama Pengguna</label>
	<div class="input-icon">
 		<i class="fa fa-user"></i>
		<input id="username" class="form-control placeholder-no-fix" pattern=".{5,}" type="text" autocomplete="off" placeholder="Nama Pengguna" name="username" onchange="checkLength()" required title="nama pengguna must inputed (min 5 characters)">
	</div>
</div>
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感谢。

4 个答案:

答案 0 :(得分:1)

您可以创建<?php if(!isset($_SESSION['UserName']) && $_SESSION['UserName']== "") { include 'Form.php'; } else { echo "Logged in"; } ?> 并根据建议添加p tag,即字符长度应小于errors,如下所示,我甚至在条件下做了一些修正。

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5
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var textbox = document.getElementById("username");
var pr = document.createElement("p");
function nm(){
	if(textbox.value.length >= 1 && textbox.value.length <= 5){
  pr.textContent = "min 5 characters";
  document.body.appendChild(pr);
  }
  else if(textbox.value.length === 0){
  pr.textContent = "nama pengguna must inputed";
  document.body.appendChild(pr);  
  }
}
textbox.addEventListener("blur",nm);
&#13;
p{
  color:red;
}
&#13;
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&#13;

答案 1 :(得分:0)

如果您想相应地更改消息,您将与HTML5验证作斗争,但这不会是一个太大的问题。

您需要做的是在数据发生变化时检查值。

将以下内容放入您的stattup代码中:

document.querySelector('input#username').onchange=function() {
    checkLength();
}

通过启动代码,我指的是用于启动脚本的任何内容。通常情况下它是这样的:

document.addEventListener('DOMContentLoad',init,false);
function init() {

}

或者,对于旧浏览器,

window.onload=init;

答案 2 :(得分:0)

如果您想将转换提醒转换为简单的短信,请按照以下代码进行操作。

<强> HTML

<div class="form-group required2">
        <label class="control-label visible-ie8 visible-ie9">Nama Pengguna</label>
        <div class="input-icon">
            <i class="fa fa-user"></i>

            <input id="username" class="form-control placeholder-no-fix" pattern=".{5,}" type="text" autocomplete="off" placeholder="Nama Pengguna" name="username" required title="nama pengguna must inputed (min 5 characters)" />
<span class="username_error" class="error"></span>
</div>  
    </div>

<强>的Javascript

<script>
    function checkLength(){
        var textbox = document.getElementById("username");
        if(textbox.value.length <= 5){
            document.getElementById('username_error').innerHTML = "min 5 characters";
        }
        else(textbox.value.length == 0){
            document.getElementById('username_error').innerHTML = "nama pengguna must inputed";
        }
    }
</script>

<强> CSS

<style>
.error{
  color:"red";
}
</style>

答案 3 :(得分:0)

试试这个:

<强> HTML

<div class="form-group required2">
  <label class="control-label visible-ie8 visible-ie9">Nama Pengguna</label>
  <div class="input-icon"> <i class="fa fa-user"></i>
    <input id="username" class="form-control placeholder-no-fix" type="text" autocomplete="off" placeholder="Nama Pengguna" name="username" required title="nama pengguna must inputed (min 5 characters)" onKeyUp="checkLength()">
    <br>
    <span style="color:#A42022" id="error"></span> </div>
</div>

<强> JAVASCRIPT

<script>
function checkLength() {
    var textbox = document.getElementById("username");
    if(textbox.value.length == 0){
        document.getElementById('error').innerHTML = "nama pengguna must inputed";
    } else if(textbox.value.length < 5) {
        document.getElementById('error').innerHTML = "min 5 characters";
    } else {
        document.getElementById('error').innerHTML = "";    
    }

}
</script>