How to use regular expressions to verify the registry-JS Tutorial-php.cn

How to use regular expressions to verify the registry

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Release： 2018-03-29 14:17:26

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This time I will bring you the use of regular expressions to verify the registry and the precautionsof using regular expressions to verify the registry. The following are practical cases. , let’s take a look.

Regular expression

Regular expression is a logical formula for stringoperation, which is to use prior Some defined specific characters and the combination of these specific characters form a "rule string". This "rule string" is used to express a filtering logic for strings.

Purpose of regular expression

1. Whether the given string conforms to the filtering logic of the regular expression (called "matching") ;

2. We can get the specific part we want from the string through regular expressions.

The characteristics of regular expressions are

1. Flexibility, logic and functionality are very strong;

2. It can quickly achieve complex control of strings in an extremely simple way;

3. It is relatively obscure for those who are new to it.

Registry verification

1. Get id

function $(id){
  return document.getElementById(id);
}

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2. Verify name

function checkName(){
  //获取值
  var username=$('user').value;
  //判断不能为空
  if(username==''){
    $('s1').innerHTML='用户名不能为空';
    return false;
  }
  //正则表达式
  var reg=/^[a-zA-Z][a-zA-Z0-9]{4,9}$/;
  //检测输入内容是否匹配正则表达式
  if(!reg.test(username)){
    $('s1').innerHTML='用户名必须是5-10位数字或字母组成，开头不能是数字'；
    return false;
  }
  //匹配，返回空
    $('s1').innerHTML='';
    return true;
}

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Remarks :s1 is the judgment prompt content, added after the input box

3.Verify password

function checkPwd(){
  //获得值
    同上…
  //判断不能为空
    同上…
  //正则表达式
  var reg=/^\S{6,}$/;
  //检测输入内容是否匹配正则表达式
  if(reg.test(password)==false){
    $('s2').innerHTML='密码必须是6位以上';
    return false;
  }
  //匹配，返回空
    同上…
}

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4.Verify email

function checkEmail(){
  //获得值
    同上…
  //判断不能为空
    同上…
  //正则表达式
  var reg=/^\w+@\w+\.com|cn|net$/;      
  //检测输入内容是否匹配正则表达式
  if(!reg.test(email)){
    $('s3').innerHTML='邮箱不合法';
    return false;
  }
  //匹配，返回空
    同上…
}

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5.Verify mobile phone number

function checkTel(){
  //获得值
    同上…
  //判断不能为空
    同上…
  //正则表达式
  var reg=/^1[34578]\d{9}$/;     
  //检测输入内容是否匹配正则表达式
  if(!reg.test(tel)){
    $('s4').innerHTML='手机号码不合法';
    return false;
  }
  //匹配，返回空
    同上…
}

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6.Verify ID number

function checkCid(){
  //获得值
    同上…
  //判断不能为空
    同上…
  //正则表达式
  var reg=/^\d{15}$|^\d{17}\d|x$/;     
  //检测输入内容是否匹配正则表达式
  if(!reg.test(cid)){
    $('s5').innerHTML='身份证不合法';
    return false;
  }
  //匹配，返回空
    同上…
}

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7.Verify QQ number

function checkQQ(){
  //获得值
    同上…
  //判断不能为空
    同上…
  //正则表达式
  var reg=/^[1-9]\d{7,10}$/;     
  //检测输入内容是否匹配正则表达式
  if(!reg.test(qq)){
    $('s6').innerHTML='QQ必须是8到11数字组成，开头不能是0';
    return false;
      }
  //匹配，返回空
    同上…
}

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8.Check all conditions

function checkAll(){
  if(checkName()&&checkPwd()&&checkEmail()&&checkTel()&&checkCid()&&checkQQ()){
    return true;
  }else{
    return false;
  }
}

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Of course, in the later stage, you can use the jQuery Validate verification framework for expression verification, which is more convenient.

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!