Discovering items located within other items

Question

Discovering items located within other items

I am currently attempting to search through an object array in order to find any objects that contain the specific object I am seeking. Once found, I want to assign it to a variable.

The interface being used is for an array of countries, each containing its own array of cities.

import { ICity } from "./city";

export interface ICountry {
    name: string,
    capital: string,
    language: string,
    population: number,
    density: number,
    area: number,
    majorCities: ICity[]
}

The city parameter in this function is what I am searching for, but it always returns undefined. What would be the most effective method to locate the country to which a given city belongs?

remove(city: ICity): void {
    var country;
    this.countries.forEach(cn => {
      if (cn.majorCities.includes(city)) {
        country = cn;
        console.log(cn);
      }
    });
    console.log(country);
  }

javascript angular typescript

Answer 1

Answer №1

In my perspective, the most effective approach is to include the country id in the city data for easier reference.

Alternatively, you could implement it as shown below:

remove(city: ICity): void {
  var country;
  this.countries.forEach((cn) => {
    if (cn.majorCities.find(c => c.toLowerCase() === city.toLowerCase())) {
      country = cn;
      console.log(cn);
    }
  });
  console.log(country);
}

Answer 2

In my perspective, the most effective approach is to include the country id in the city data for easier reference.

Alternatively, you could implement it as shown below:

remove(city: ICity): void {
  var country;
  this.countries.forEach((cn) => {
    if (cn.majorCities.find(c => c.toLowerCase() === city.toLowerCase())) {
      country = cn;
      console.log(cn);
    }
  });
  console.log(country);
}

Answer 3

Answer №2

It's important to remember that your ICity type object is not just a simple string; therefore, a straightforward check like the following:

if (cn.majorCities.includes(city))

will only return true if one of the elements in majorCities matches the instance referenced by the city variable.

Since the ICity interface likely includes a property like name, such as:

interface ICity {
name: string
}

you should be checking for a string-type property like this:

if (cn.majorCities.some((el) => {
        return el.name == city.name

    })) {
    // do something
}

Answer 4

It's important to remember that your ICity type object is not just a simple string; therefore, a straightforward check like the following:

if (cn.majorCities.includes(city))

will only return true if one of the elements in majorCities matches the instance referenced by the city variable.

Since the ICity interface likely includes a property like name, such as:

interface ICity {
name: string
}

you should be checking for a string-type property like this:

if (cn.majorCities.some((el) => {
        return el.name == city.name

    })) {
    // do something
}

Answer 5

Answer №3

One potential solution is shown below:

const countries = [{
    name: 'Iran',
    cities: ['Shiraz', 'Tehran']
  },
  {
    name: 'Germay',
    cities: ['Berlin']
  }
]

const findCity = (city) => {
  countries.forEach(country => {
    if (country.cities.includes(city))
      console.log(city, 'has been found!')

  })
}
findCity('Shiraz')

Answer 6

One potential solution is shown below:

const countries = [{
    name: 'Iran',
    cities: ['Shiraz', 'Tehran']
  },
  {
    name: 'Germay',
    cities: ['Berlin']
  }
]

const findCity = (city) => {
  countries.forEach(country => {
    if (country.cities.includes(city))
      console.log(city, 'has been found!')

  })
}
findCity('Shiraz')

Discovering items located within other items

Answer №1

Answer №2

Answer №3

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