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Transform Functions

Transform functions allow you to format cell values before display without modifying the original data. This is useful for currency formatting, date conversion, string manipulation, and any other display transformations.

Basic String Transform​

import { Table } from 'console-table-printer';

const p = new Table({
  columns: [
    { name: 'original', alignment: 'left' },
    {
      name: 'uppercase',
      alignment: 'left',
      transform: (value) => String(value).toUpperCase()
    },
  ],
});

p.addRow({ original: 'hello', uppercase: 'hello' });
p.addRow({ original: 'world', uppercase: 'world' });
p.addRow({ original: 'test', uppercase: 'test' });

p.printTable();
Screenshot

Currency Formatting​

One of the most common use cases is formatting numbers as currency:

import { Table } from 'console-table-printer';

const p = new Table({
  columns: [
    { name: 'item', alignment: 'left' },
    {
      name: 'price',
      alignment: 'right',
      transform: (value) => `$${Number(value).toFixed(2)}`
    },
  ],
});

p.addRows([
  { item: 'Coffee', price: 3.5 },
  { item: 'Sandwich', price: 7.99 },
  { item: 'Water', price: 1 },
]);

p.printTable();
Screenshot