How to change order/sequence of columns in material table without any functionality angular

Question

I want to change order or sequence of material table columns and data is coming from api in json form.

where I am creating headers and columns from API data itself

Answer 1

You can just adjust the position of the values. Using the array methods splice, slice, unshift, push we can do the transformations.

import {Component} from '@angular/core';
import {MatTableModule} from '@angular/material/table';

export interface PeriodicElement {
  name: string;
  position: number;
  weight: number;
  symbol: string;
}

const ELEMENT_DATA: PeriodicElement[] = [
  {position: 1, name: 'Hydrogen', weight: 1.0079, symbol: 'H'},
  {position: 2, name: 'Helium', weight: 4.0026, symbol: 'He'},
  {position: 3, name: 'Lithium', weight: 6.941, symbol: 'Li'},
  {position: 4, name: 'Beryllium', weight: 9.0122, symbol: 'Be'},
  {position: 5, name: 'Boron', weight: 10.811, symbol: 'B'},
  {position: 6, name: 'Carbon', weight: 12.0107, symbol: 'C'},
  {position: 7, name: 'Nitrogen', weight: 14.0067, symbol: 'N'},
  {position: 8, name: 'Oxygen', weight: 15.9994, symbol: 'O'},
  {position: 9, name: 'Fluorine', weight: 18.9984, symbol: 'F'},
  {position: 10, name: 'Neon', weight: 20.1797, symbol: 'Ne'},
];

/**
 * @title Basic use of `<table mat-table>`
 */
@Component({
  selector: 'table-basic-example',
  styleUrls: ['table-basic-example.css'],
  templateUrl: 'table-basic-example.html',
  standalone: true,
  imports: [MatTableModule],
})
export class TableBasicExample {
  displayedColumns: string[] = ['position', 'name', 'weight', 'symbol'];
  dataSource = ELEMENT_DATA;

  ngOnInit() {
    setInterval(() => {
      // you can just change the order of the columns it will update on the grid!
      this.displayedColumns = shuffle(this.displayedColumns);
    }, 5000)
  }
}


function shuffle(array: any) {
  let currentIndex = array.length,  randomIndex;

  // While there remain elements to shuffle.
  while (currentIndex > 0) {

    // Pick a remaining element.
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex--;

    // And swap it with the current element.
    [array[currentIndex], array[randomIndex]] = [
      array[randomIndex], array[currentIndex]];
  }

  return array;
}

stackblitz

reference answer for shuffle logic