JavaScript verification number code example in Number(4,1) format sharing

This article mainly introduces the JavaScript verification number example code in Number(4,1) format. The implementation ideas of this article are clear and the code is simple and easy to understand. It is very good and has reference value. Friends in need You can refer to the

project below. There is an entry that requires digital format verification. The front-end uses the miniUI framework. The miniUI document comes with verification, vtype="float", which verifies floating point numbers. However, it cannot verify how many integers and decimals there are in this floating point number, so it is necessary to rewrite a js function to verify:

Implementation ideas:

1. Get the filled-in value

2. Determine whether it is empty. If not, execute 3

3. Trim() the string to remove spaces, and judge whether it is empty or not. .” If the beginning or end of the number is not a legal number, a prompt will be given.

4. Determine in advance whether the string is true or false, because the Number function will be used below, which can convert true and false into 1 and 0, so it needs to be judged before use. If the string is this Then a prompt will be given

5. Use the Number function to convert the string into a number. If the converted value is 0, it means that the original string is empty; if the converted number is NaN, it means that the original character Strings are not purely numeric strings. Corresponding prompts will be given. If it is a pure numeric string, execute 6

6. Convert the converted value to the String type. First determine whether the length of the value is legal. If it is not legal, give A prompt will appear, and it is legal to execute 7

7. Determine whether the integer bits of the value conform to the definition of the Number type, and it is greater than the minimum value and less than or equal to the maximum value. If it is legal to execute 8, a prompt will be given if it is illegal;

8. To determine the decimal place, use the substring() function. If it is legal, return true; otherwise, a corresponding error message will be given.

Implementation code:

 //校验number(4,1)
  function check(v){
   var str = mini.get(v).getValue();
   //非空
   if(str!=null && str.length>0){
    str = str.trim();//去掉空格
    if(str.substring(0,1)=="." || str.substring(str.length-1)=="."){
     mini.alert("请输入有效的数值");
     return false;
    }
    //排除Boolean值
    if(str==true||str==false){
     mini.alert("请输入合法的数值");
     return false;
    }else {
     var num = Number(str);//将字符串转为数字类型
     if(num == 0){//输入的字符串为空
      mini.alert("请输入合法的值");
      return false;
     }else if(isNaN(num)==true){//输入的为非数字型字符串
      mini.alert("请输入合法的值");
      return false;
     }else {//纯数字字符
      num = num.toString();
      var numLenth = num.length;
      if (numLenth >5) {
       mini.alert("数值超过有效长度");
       return false;
      }else{//有效数字
       var pointIndex = num.indexOf(".");
       if (num.substring(0,pointIndex).length>3 || num.substring(0,pointIndex).length<=0) {//整数部分必须在1-3位数字
        mini.alert("整数部分有效数字长度超过有效范围");
        return false;
       }else if(pointIndex>0){//判断小数部分
        if(num.substring(pointIndex).length>2 ||(num.substring(pointIndex).length==1)){
         mini.alert("小数部分不是有效的");
         return false;
        }
       }
      }
     }
    }
   }
   return true;
  }

The above is the detailed content of JavaScript verification number code example in Number(4,1) format sharing. For more information, please follow other related articles on the PHP Chinese website!