Append to variable using class

Question

I create UrlParamClass and i want to know, how i can append value. See this example:

class UrlParam {
    append = (key, value) => {
        return `&${key}=${value}`
    }
}

let param = new UrlParam()

param.append('module','clothes')
param.append('module','shoes')
param.append('module','gloves')


console.log(param) //i want to see: &module=clothes&module=shoes&module=gloves

You aren't *doing* anything with the result of the function, least of all storing it in the object, and neither do you have a `toString` method that would give you what you want. — Niet the Dark Absol, Oct 11 '18 at 09:30

cнŝdk · Accepted Answer · 2018-10-11T09:46:41.050

If you are using a Class, what you can do is to use an inner instance attributein your class.

Initialize it in your constructor and keep changing it in your append method:

class UrlParam {
  constructor(value) {
    this.value = value;
  }
  append(key, value){
    this.value += `&${key}=${value}`
  }
}

let param = new UrlParam('');

param.append('module', 'clothes')
param.append('module', 'shoes')
param.append('module', 'gloves')


console.log(param) //i want to see: &module=clothes&module=shoes&module=gloves

Logar · Answer 2 · 2018-10-11T09:52:10.840

If you're going to write a class, I'd go for this approach :

First, initialize your object with an empty params array
Then, feed the instance's array within the append method
Lastly, write a toString method that will "glue" the params together with the expected syntax

class UrlParam {
    constructor() {
        this.params = [];
    }

    append(key, value) {
        this.params.push({key, value});
    }

    toString() {
        return this.params
            .map(({key, value}) => `&${key}=${value}`)
            .join('');
    }
}

let param = new UrlParam();
param.append('module', 'clothes')
param.append('module', 'shoes')
param.append('module', 'gloves')

console.log(param.toString());

Append to variable using class

2 Answers2