the task we are going to perform in this article is about how to add a regular expression that an input elements value is checked against in html.
将用于检查输入元素值的正则表达式由html的d5fd7aea971a85678ba271703566ebfd模式属性指定。以下输入类型与此属性兼容：文本、密码、日期、搜索、电子邮件等。
syntax以下是html d5fd7aea971a85678ba271703566ebfd标签的pattern属性的语法。
<input pattern = regular_exp>
for getting more idea on how to add a regular expression that an input elements value is checked against in html, let’s look into the following examples
对于type=passwordthe type=password attribute on the <input> tag creates a text field where users can safely enter a password. depending on the browser, characters are replaced as they are entered by a dot (•) or asterisk (*).
example在下面的示例中，我们使用了<input>元素，其类型为”password”。
<!doctype html><html><body> <form action=#> <label for=tutorial>password:</label> <input type=password id=tutorial name=tutorial pattern=.{8,} title=eight or more characters> <input type=submit> </form></body></html>
在执行上述脚本时，它将生成一个类型为密码的输入字段，并设置一个模式以确保它满足限制条件才能提交，否则将显示一个警示框。
for input field restricted with three letters在这种情况下，我们限制了输入字段，只允许用户输入三个字母。
exampleconsidering the following we are using the input field restricted with three letters with no numbers or special characters.
<!doctype html><html><body> <form action=#> <label for=tutorial>country code:</label> <input type=text id=tutorial name=tutorial pattern=[a-za-z]{3} title= country code><br><br> <input type=submit> </form></body></html>
当脚本被执行时，它将显示一个带有名称“countrycode”的输出，以及一个仅限于三个字母的提交按钮。如果不符合限制，它将显示一个警告框。
以上就是如何在html中添加一个用于检查输入元素值的正则表达式？的详细内容。