Get object name from list-CodePudding

I have something that looks like this:

const Books = <Map<String, dynamic>>[
  {'name': 'The book 1', 'price': 30},
  {'name': 'The book 2', 'price': 50},
];
const Newspapper = <Map<String, dynamic>>[
  {'name': 'The Newspapper 1', 'price': 4},
  {'name': 'The Newspapper 2', 'price': 9},
];

What's the best way so I can call the name of the variable? It's even possible to print the variable name? For example, print('you are reading $booksvariable') // you are reading books

also tried with something simmilar

const allList = <Map<String, dynamic>>[
  {
    "books": [
  {'name': 'The book 1', 'price': 30},
  {'name': 'The book 2', 'price': 50},
    ]
  },
   {
    "newspapper": [
   {'name': 'The Newspapper 1', 'price': 4},
  {'name': 'The Newspapper 2', 'price': 9},
    ]
  }
];

But still can't manage to disnplay only the "books" and "newspapper".

CodePudding user response：

print(books); //you are reading [{name: The book 1, price: 30}, {name: The book 2, price: 50}]
print(books[1]); //you are reading {name: The book 2, price: 50}
print(allList); //you are reading [{books: [{name: The book 1, price: 30}, {name: The book 2, price: 50}]}, {newspapper: [{name: The Newspapper 1, price: 4}, {name: The Newspapper 2, price: 9}]}]


books.map((e) => print('you are reading ${e['name']}')).toList(); //you are reading The book 1   \n    you are reading The book 2

allList.elementAt(0).map((key, value) {
  print(value); //  [{books: [{name: The book 1, price: 30}, {name: The book 2, price: 50}]}, {newspapper: [{name: The Newspapper 1, price: 4}, {name: The Newspapper 2, price: 9}]}]
  return MapEntry(key, value);
});

books.forEach((element) {
  print('you are reading ${element['name']}'); //you are reading The book 1  \n you are reading The book 1
});

CodePudding user response：

If your goal is to combine the two Lists and just print out the name this will suffice:

const Books = <Map<String, dynamic>>[
  {'name': 'The book 1', 'price': 30},
  {'name': 'The book 2', 'price': 50},
];
const Newspapper = <Map<String, dynamic>>[
  {'name': 'The Newspapper 1', 'price': 4},
  {'name': 'The Newspapper 2', 'price': 9},
];

// Combine the two lists
var combinedList = [];
combinedList.addAll(Books);
combinedList.addAll(Newspapper);

// Get the names by mapping them and print them
var names = combinedList.map((b) => b['name']);
names.forEach((name) {
  print("You are reading $name");
});

Output:

I/flutter (20249): You are reading The book 1
I/flutter (20249): You are reading The book 2
I/flutter (20249): You are reading The Newspapper 1
I/flutter (20249): You are reading The Newspapper 2

If you want to print those two seperately you can do this:

const Books = <Map<String, dynamic>>[
  {'name': 'The book 1', 'price': 30},
  {'name': 'The book 2', 'price': 50},
];
const Newspapper = <Map<String, dynamic>>[
  {'name': 'The Newspapper 1', 'price': 4},
  {'name': 'The Newspapper 2', 'price': 9},
];

// Get the names and print them
Books.forEach((book) {
  print("You are reading the book ${book['name']}");
});

Newspapper.forEach((newspapper) {
  print("You are reading the newpaper ${newspapper['name']}");
});

Output:

I/flutter (20249): You are reading the book The book 1
I/flutter (20249): You are reading the book The book 2
I/flutter (20249): You are reading the newpaper The Newspapper 1
I/flutter (20249): You are reading the newpaper The Newspapper 2

It is up to you if you want to map the name first (like in the first example) or just access the name directly in the loop (like ${book['name']} in the second example). Hope I could help.