`

Here's the code written in TypeScript.

This is code to build HTML table which display items from Nested objects. This code works fine but just there is an issue in printing like it should only create table with rows but it is also printing some coma's which are not even part of any line which is executed

import {Component} from '@angular/core';
  
@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})

export class AppComponent {
  title = 'Angular';
  data = {
    id: '0001',
    type: 'donut',
    name: 'Cake',
    ppu: 0.55,
    batters: {
      batter: [{
          id: '1001',
          type: 'Regular'
        },
        {
          id: '1002',
          type: 'Chocolate'
        },
        {
          id: '1003',
          type: 'Blueberry'
        },
        {
          id: '1004',
          type: "Devil's Food"
        }
      ]
    },
    topping: [{
        id: '5001',
        type: 'None'
      },
      {
        id: '5002',
        type: 'Glazed'
      },
      {
        id: '5005',
        type: 'Sugar'
      },
      {
        id: '5007',
        type: 'Powdered Sugar'
      },
      {
        id: '5006',
        type: 'Chocolate with Sprinkles'
      },
      {
        id: '5003',
        type: 'Chocolate'
      },
      {
        id: '5004',
        type: 'Maple'
      }
    ]
  };

  //Function which build HTML Table which get's dynamic values.

  htmlStr = (data, wrapperClassName, tableClassName = 'table table-sm') => {
    return `
    <div class=${tableClassName}>
      <table className=${tableClassName}>

        <tbody>

          ${Object.keys(data).map( (k) => `
          <tr>
            ${(!Array.isArray(data) && `
            <td>${k.replace(/_/g, ' ')}</td>`) || ''} ${ data[k] && typeof data[k] === 'object' ? `
            <td>
              ${this.htmlStr(data[k], wrapperClassName, tableClassName)}
            </td>` : `
            <td>
              <span>${data[k] || ''}</span>
            </td>` }
          </tr>` )}
        </tbody>

      </table>

    </div>`;
  };
}

CodePudding user response：

in your code the snippet Object.keys(data).map(.....) converts it to array. Now when you put this array in string literal JavaScript will try to convert it to a string so it will call .toString() on it which joins all the elements of array using , by default.

instead do this Object.keys(data).map(....).join("") this will join array with empty string