CODEWITHSUNDEEP
javascriptmultidimensional-array
J. Doe
J. Doe

Reputation: 1

Javascript Multi-Dimensional Array Problems

I can't figure away around this, I want the MD array to store the name of a book and the price. I know this is easier with two arrays but really wanted to give a MD array ago in javascript. I have tried several ways but can only get the book name or the book price to display twice. Any help would be greatly appreciated. 

var bookName = new Array();

for (var i = 0; i < 3; i++) 
{
bookName[i] = new Array();

    for (var j = 0; j < 1; j++) 
    {
        bookName[i] = prompt("Please enter book name!");
        bookName[[i][j]] = prompt("Please enter book price!");
        document.write(bookName[i] + bookName[[i][j]] + "</br>");
    }
}

Upvotes: 0

Views: 1213

Answers (7)

Hubert Boma Manilla
Hubert Boma Manilla

Reputation: 128

var bookName = [];

for (var i = 0; i < 3; i++)

{
  var b = bookName[i];
  b = [];
  for (var j = 0; j < 1; j++) 
  {
    bookName[i] = prompt("Please enter book name!");
    b[j] = prompt("Please enter book price!");
    document.write(bookName[i] + b[j] + "</br>");
  }
}

This should do it..

Upvotes: 0

Bergi
Bergi

Reputation: 664196

I'm not sure what you are doing there. Please make yourself familiar with the concept of Arrays, Objects and accessing of properties in JavaScript.

var bookName = new Array();

for (var i = 0; i < 3; i++) 
{
bookName[i] = new Array();
// the i. item of bookname holds an empty array now

    for (var j = 0; j < 1; j++) 
    {
        bookName[i] = prompt("Please enter book name!");
// you're overwriting the array just created with a string now
        bookName[[i][j]] = prompt("Please enter book price!");
// this is absolutely invalid syntax
        document.write(bookName[i] + bookName[[i][j]] + "</br>");
// as well as this
    }
}

What you wanted to do:

var bookName = new Array();
for (var i = 0; i < 3; i++) {
    bookName[i] = new Array();
    for (var j = 0; j < 1; j++) {
        // this is absolute ugly in a for loop:
        if (j==0)
            bookName[i][j] = prompt("Please enter book name!");
        else if (j==1)
            bookName[i][j] = prompt("Please enter book price!");
    }
    // direct accessing is better:
    document.write(bookName[i][0] + bookName[i][1] + "</br>");
}

but it would be much easier so:

var bookName = [];
for (var i = 0; i < 3; i++) {
    bookName[i] = {
        name: prompt("Please enter book name!"),
        price: prompt("Please enter book price!")
    };
    document.write(bookName[i].name + bookName[i].price + "</br>");
}

Upvotes: 0

Esailija
Esailija

Reputation: 140210

A multidimensional array doesn't make much sense here, you probably want an array of objects. 

var books = [], i = 3;

while( i-- ) {
    books.push({
        name: prompt("Please enter book name!"),
        price: prompt("Please enter book price!")
    });
}

Upvotes: 0

Churk
Churk

Reputation: 4627

u r overwriting your bookName[i]

bookName[i] = new Array(); and bookName[i] = prompt("Please enter book name!");

try this:

var bookName = new Array();
for (var i = 0; i < 3; i++)  {
    bookName[i] = new Array();
    for (var j = 0; j < 1; j++)  {
        var name = prompt("Please enter book name!");
        var price = prompt("Please enter book price!");
        bookName[i][j] = {name:name, price:price}
        document.write(bookName[i][j].name + bookName[i][j].price + "</br>");
    }
}

Upvotes: 0

Peter Olson
Peter Olson

Reputation: 142911

I think you should just use an array of objects for this:

var books = [];
for(var i = 0; i < 3; i++) {
  books.push({
    name: prompt("Please enter book name!"),
    price: prompt("Please enter book price!")
  });
  document.write(books[i].name + books[i].price + "</br>");   
}

If you prefer, you can do an array of arrays instead:

var books = [];
for(var i = 0; i < 3; i++) {
  books.push([prompt("Please enter book name!"), prompt("Please enter book price!")]);
  document.write(books[i][0]+ books[i][1] + "</br>");   
}

Upvotes: 5

Benubird
Benubird

Reputation: 19467

Instead of this:

bookName[i] = prompt("Please enter book name!");
bookName[[i][j]] = prompt("Please enter book price!");
document.write(bookName[i] + bookName[[i][j]] + "</br>");

Do this:

bookName[i][j][0] = prompt("Please enter book name!");
bookName[i][j][1] = prompt("Please enter book price!");
document.write(bookName[i][j][0] + bookName[i][j][1] + "</br>");

I don't think I've ever seen var[[i][j]] format before...

Upvotes: 0

bfavaretto
bfavaretto

Reputation: 71908

Here is how you build a 2D array:

var bookName = new Array();
for (var i = 0; i < 3; i++) 
{
    bookName[i] = new Array();
    bookName[i][0] = prompt("Please enter book name!");
    bookName[i][1] = prompt("Please enter book price!");
    document.write(bookName[i] + bookName[i][0] + ": " + bookName[i][1] + "</br>");
}

You could also do that with objects inside the array:

var bookName = new Array();
for (var i = 0; i < 3; i++) 
{
    bookName[i] = {};
    bookName[i]["name"] = prompt("Please enter book name!");
    bookName[i]["price"] = prompt("Please enter book price!");
    document.write(bookName[i] + bookName[i].name + ": " + bookName[i].price + "</br>");
}

Upvotes: 4

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