"SyntaxError: Unexpected identifier" in javascript class

Question

I have two function in my javascript class where one function is called in another function, I have use the parameter how I use in other programming language. But it is throwing me

"SyntaxError: Unexpected identifier"

class IpSubnetMatch {


 function ip2longConvert(ip)
  {
  var components;
  if(components = ip.match(/^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/))
  {
    var iplong = 0;
    var power = 1;
    for(var i=4; i>=1;i--)
      {
        iplong += power * parseInt(components[i]);
        power *= 256;
      }
    return iplong;
  }
  else return -1;
}

function inSubNet(ip,subnet)
{
  var mask, base_ip;
  var long_ip = ip2longConvert(ip);
  if((mask = subnet.match(/^(.*?)\/(\d{1,2})$/)) && ((base_ip = ip2longConvert(mask[1])) >= 0))
    {
      var freedom = Math.pow(2,32 - parseInt(mask[2]));
      return(long_ip > base_ip) && (long_ip < base_ip + freedom -1);
    }
  else return false;
}
}

let user = new IpSubnetMatch();
user.inSubNet('10.1.5.5', '10.1.0.0/16');

Normally you want to leave the original code so we can understand the nature of the question when someone reads it in the future. — ChaosPandion
– ChaosPandion, Commented Apr 8, 2019 at 17:59

ChaosPandion · Accepted Answer · 2019-04-08 17:36:16Z

2

You need to define methods in the class. You also may want to define them as static since they really don't depend on any instance state.

class IpSubnetMatch {
    ip2longConvert(ip) {
        // ...
    }
    inSubNet(ip,subnet) {
        const long_ip = this.ip2longConvert(ip);
        // ...
    }
}

edited Apr 8, 2019 at 17:36

answered Apr 8, 2019 at 16:29

ChaosPandion

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5 Comments

ChaosPandion Over a year ago

@cyborg - I've updated to include accessing other methods of the class.

cyborg Over a year ago

Nope, facing the same issue. I have updated question with your suggestion but getting following error "TypeError: Cannot read property 'inSubNet' of undefined

ChaosPandion Over a year ago

@cyborg - That is strange I ran the code you just reverted and it works. jsfiddle.net/64xz2kmg

ChaosPandion Over a year ago

@cyborg - I'm seeing true show up in the console and no TypeError.

cyborg Over a year ago

Without console how should I get the output as true ?

Razana N. · Accepted Answer · 2019-04-08 17:31:28Z

2

Classes in JavaScript do not actually offer additional functionalities and are often described as providing "syntactical sugar" over prototypes and inheritance. ES6 Classes offer a cleaner and more elegant syntax.

class IpSubnetMatch {
    constructor() {

    }

    ip2longConvert(ip) {

    }

    inSubNet(ip,subnet) {
       //Call methods using this keyword.
       this.ip2longConvert(ip);   
    }
}

Class methods do not use the function keyword in class syntax. Use this keyword to reference methods or properties.

answered Apr 8, 2019 at 17:31

Razana N.

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Comments

pr-olga · Accepted Answer · 2019-04-08 16:37:54Z

0

The keyword function is the problem. Since ECMA2015 you should use arrow functions.

answered Apr 8, 2019 at 16:37

pr-olga

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