索引签名参数类型必须是“字符串”或“数字”

Question

I building an E-shop in React with typescript where I have a Cart and a CartItem class as shown below:

export class CartItem {
  public id: bigint;

  public file: File;

  public constructor(file: File) {
    this.id = file.id;
    this.file = file;
  }
}

export class Cart{
  public items: { [id: bigint]: CartItem };

  public constructor() {
    this.items = {};
  }
}

The issue is that An index signature parameter type must be either 'string' or 'number' Right now its necessary for id to be bigint which isn't compatible as an index signature parameter. Any suggestions on how to solve this?

Answer 1

You can simply cast your bigint to a string.

Alternatively, you can also take the hash of the bigint. This will give you a set length for your string and might work better if you work with truly giant numbers.

If you need the original id, just add it to the basketitem class if you're using the hash aproach.