尝试使用非常简单的验证创建表单,我很好奇两件事。
一个;如何检查表单是否为空?
两个;在电话号码字段中,我如何才接受以这种格式的号码:
xxx-xxxx(其中X是数字)
这是我到目前为止所做的:
HTML:
<form onsubmit="return false" method="post" name="myForm">
<div class="form-block">
<label>Name: </label>
<input type="text" name="name" id="name" />
<span id="name-error" class="error"></span>
</div>
<div class="form-block">
<label>Phone Number: </label>
<input type="text" name="phone" id="phone" />
<span id="phone-error" class="error"></span>
</div>
<input type="submit" id="mysubmit" name="submit" onclick="validate()" />
</form>
CSS:
a, p, h1, h2, h3, h4, h5, h6, li, label, span {
font-family: sans-serif;
}
#mysubmit {
display: block;
margin-top: 10px;
}
span.error {
color: red;
font-weight: bold;
}
.form-block {
display: block;
width: 100%;
margin: 10px 0;
}
label {
display: inline-block;
width: 150px;
text-align: right;
}
JS:
validate = function() {
var name = document.getElementById("name").value;
var phone = document.getElementById("phone").value;
if(/^[a-zA-Z]*$/.test(name)) {
document.getElementById("name-error").innerHTML = "Good.";
} else {
document.getElementById("name-error").innerHTML = "Invalid. Only letters.";
}
if(isNaN(phone)) {
document.getElementById("phone-error").innerHTML = "Can only contain numbers";
} else {
document.getElementById("phone-error").innerHTML = "Good.";
}
};
答案 0 :(得分:0)
只需检查空字符串,即可测试表单元素的值是否为空。
我已经posted something可以帮助您访问和遍历表单字段。
// ES5: a very crude validation check
// your form field elements should share a class in order to collect them all
var formElements = document.querySelectorAll('.your-form-field-class');
// set a flag to keep track of whether you have an empty field
var containsEmptyField = false
i,
l = formElements.length;
for (; i < l; i++) {
if (formElements[i].value === '') {
containsEmptyField = true;
// do something in response to an empty field
// the break is to stop looping since you've found
// a match
break;
}
}
// ES6: a very crude validation check
const formElements = document.querySelector('#some-form').elements;
let containsEmptyField = false;
for (let element of formElements) {
if (element.value === '') {
containsEmptyField = true;
break;
}
}
我没有正确测试,但电话号码的正则表达式可能如下所示:
(/^(\d){3,3}\-(\d){4,4}$/).test(someNumber)
// returns true if value matches or false if it doesn't