Fill 2D array "line by line" JavaScript/NodeJS

Question

Hello I am struggling with arrays in JavaScript/NodeJS.

Basically, here is my code:

let arr = new Array();

arr = {
  "Username" : var1,
  "Console"  : var2,
  "Pseudo"   : var3,
}

console.log(arr);

var1, 2 and 3 contains my data that is changing each time.

Let's consider for our first case:

var1 is "Johnson"
var2 is "ps4"
var3 is "Johnson46"

The code above would display the following:

{ Username: 'Johnson', Console: 'ps4', Pseudo: 'Johnson46' }

Now if the data in var1, var2, and var3 change, it will replace the array's content with new data. So if var1 = "Dave", var2 = "xbox" and var3 = "Dave78", it will replace the current array and display:

{ Username: 'Dave', Console: 'xbox', Pseudo: 'Dave78' }

But instead I would like my code to print the follwing:

{ Username: 'Johnson', Console: 'ps4', Pseudo: 'Johnson46' }
{ Username: 'Dave', Console: 'xbox', Pseudo: 'Dave78' }

See? Without overriding the array, just adding my data in succession. "line by line" or "step by step" if you prefer, sorry I don't really know how to say that.

You must push a new object to your array instead modifying it — Luis felipe De jesus Munoz
– Luis felipe De jesus Munoz, Commented Aug 10, 2018 at 20:05
why initializing with an array and then assign an object? (and the name of the variable leads wrong.) — Nina Scholz
– Nina Scholz, Commented Aug 10, 2018 at 20:06

Luis felipe De jesus Munoz · Accepted Answer · 2018-08-10 20:09:20Z

3

You must push your objects to the array instead modifying it

let arr = new Array();

object1 = {
  "Username" : "Jhon",
  "Console"  : "xbox",
  "Pseudo"   : "asd",
}

arr.push(object1)

object2 = {
  "Username" : "Doe",
  "Console"  : "ps4",
  "Pseudo"   : "efg",
}

arr.push(object2)

console.log(arr);

answered Aug 10, 2018 at 20:09

Luis felipe De jesus Munoz

8,0133 gold badges38 silver badges54 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Charles Salvan Over a year ago

Thank you, I just had to edit it a litle bit but you had the right idea.

Aritra Chakraborty · Accepted Answer · 2018-08-10 20:20:32Z

0

I am going for more of a theoretical route. Maybe it will clear some of your doubt maybe it will not.

First of all, on a side note, Even though Array is technically an object but {..} is the notation for objects not arrays. If there is a object like {'0':.., '1':.., '2':..} and it has a length property then is called an array like object (thanks @Alnitak)

Now, when you are declaring an object, and adding values from variables if you're referencing an immutable object like string, number it will reference the value itself. If you're referencing say an object it will hold the object's reference and if you change the object it will change too.

For example:

const obj = {'a':'b'};

const x = {
    m: obj.a
}
console.log(x);
obj.a = 'c';
console.log(x);

This will print,

{ m: 'b' }
{ m: 'b' }

But when your code is:

const obj = {'a':'b'};

const x = {
    m: obj //referencing obj
}
console.log(x);
obj.a = 'c';
console.log(x);

It will print:

{ m: { a: 'b' } }
{ m: { a: 'c' } }

So, if you want your code to just print it then you can reference an object in your variable.

edited Aug 10, 2018 at 20:20

answered Aug 10, 2018 at 20:13

Aritra Chakraborty

12.6k3 gold badges30 silver badges37 bronze badges

1 Comment

Alnitak Over a year ago

an Object with numeric keys isn't "array like" (aka a "pseudo-array") unless it also has a .length property.

Collectives™ on Stack Overflow

Fill 2D array "line by line" JavaScript/NodeJS

2 Answers 2

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related