call function from same class nodejs

Question

I try to call function from same class but it always return an error TypeError: this.c is not a function I tried also module.exports.c() and the same result

module.exports = (options)=>{
    return{
        a:(a)=>{
           console.log(a);
        },
        b:(b)=>{
          this.c('c');
          console.log(b)
        },
        c:(c)=>{
           console.log(c);
        }
    }
}

After Updated

module.exports =  ({})=>{
    return{
        genereate:function(identifier){
            console.log('genereate')
        },
        middleware:function(req,res,next){
            this.c();
            console.log('genereate')
        },
        c:function(){
            console.log('geeet');
        }
    }
}

It's not a Class it's an Object (no this)

Dennis Vash
– Dennis Vash

2019-04-13 19:12:54 +00:00
Commented Apr 13, 2019 at 19:12 — Dennis Vash
– Dennis Vash, Commented Apr 13, 2019 at 19:12

NullDev · Accepted Answer · 2019-04-13 19:22:05Z

2

Arrow functions bind this lexically (meaning it does not bind it's own this).
Use normal function expressions instead:

module.exports = (options) => {
    return {
        a: function(a){
            console.log(a);
        },
        b: function(b){
            this.c('c');
            console.log(b)
        },
        c: function(c){
            console.log(c);
        }
    };
};

Browserfied example:

let f = (options) => {
    return {
        a: function(a){
            console.log(a);
        },
        b: function(b){
            this.c('c');
            console.log(b)
        },
        c: function(c){
            console.log(c);
        }
    };
};

f().a("a");
f().b("b");
f().c("c");

edited Apr 13, 2019 at 19:22

answered Apr 13, 2019 at 19:16

NullDev

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2 Comments

Alwaysblue Over a year ago

@MahmoudNiypoo Update your code, like what you tried so that we can help you in fixing it

NullDev Over a year ago

@MahmoudNiypoo The second code you added is invalid. Working example here.

Dennis Vash · Accepted Answer · 2019-04-13 19:27:46Z

0

You can try and export a class, just pass options to your constructor

class InnerCall {
  constructor(options) {
    this.options = options;
  }

  a(a) {
    console.log(a);
  }

  b(b) {
    this.c('c');
    console.log(b);
  }

  c(c) {
    console.log(c);
  }
}

const example = new InnerCall({ option: 'Im an option' });

example.b('check this out');
console.log(example.options.option);

edited Apr 13, 2019 at 19:27

answered Apr 13, 2019 at 19:21

Dennis Vash

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3 Comments

Mahmoud Niypoo Over a year ago

I need to pass options to InnerCall(options)

Dennis Vash Over a year ago

No problem, use constructor (I edited the answer)

Mahmoud Niypoo Over a year ago

thanks Dennis your code work fine but when I have wrote it , show up TypeError: Cannot read property 'c' of undefined this error

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