How to solve - http.get(...).map is not a function in [null] - Error in Angular?

 The error http.get(...).map is not a function in [null] occurs when you are trying to use the map operator on the response of an HTTP GET request in Angular. This error occurs because the map operator is not available on the response object returned by the HTTP GET method.

To fix this error, you need to modify your code to use the pipe operator instead of the map operator. Here is an example:

typescript
import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';

@Injectable({
  providedIn: 'root'
})
export class MyService {
  constructor(private http: HttpClient) {}

  getData(): Observable<any> {
    return this.http.get('https://jsonplaceholder.typicode.com/todos')
      .pipe(
        map(response => response)
      );
  }
}

In the above example, the map operator is replaced with the pipe operator, and the map operator is passed as an argument to the pipe method. The map operator is used to transform the response from the HTTP GET request.

By using the pipe operator, you can chain multiple operators to transform the response in different ways. In this example, the map operator simply returns the response as it is.

Note that you also need to import the map operator from the rxjs/operators module.