Retrieve the title of an item stored within a list

Question

Retrieve the title of an item stored within a list

Let's say I have an array filled with objects - exactly 10 of them, each with unique names.

var upgrades = [
tree = {price: 20, rate:0.5, owned:0},
irr = {price: 80, rate:1, owned:0},
press = {price: 150, rate:2, owned:0},
cracker = {price: 400, rate:7, owned:0},
gmo = {price: 1000, rate:10, owned:0},
shack = {price: 1500, rate:13, owned:0},
truck = {price: 2000, rate:14, owned:0},
factory = {price: 5000, rate:18, owned:0},
rr = {price: 9000, rate:25, owned:0},
mGadget = {price: 15000, rate:30, owned:0},
];

I would like to extract the name associated with each object and store it in a string variable.

var x=upgrades[0].getObjName

In theory, x should now be equivalent to 'tree'; Is there a way to achieve this without having to introduce a 'name' variable within my objects?

javascript arrays object

Answer 1

Answer №1

To ensure your code functions correctly, make sure you are creating keys for the objects in the array rather than global variables. Start by correcting the syntax to create an array of objects structured like this:

var upgrades = [
  { tree: {price: 20, rate:0.5, owned:0} },
  { irr: {price: 80, rate:1, owned:0} },
  { press: {price: 150, rate:2, owned:0} },
  { cracker: {price: 400, rate:7, owned:0} },
  { gmo: {price: 1000, rate:10, owned:0} },
  { shack: {price: 1500, rate:13, owned:0} },
  { truck: {price: 2000, rate:14, owned:0} },
  { factory: {price: 5000, rate:18, owned:0} },
  { rr: {price: 9000, rate:25, owned:0} },
  { mGadget: {price: 15000, rate:30, owned:0} },
];

Once this is done, utilize Object.keys() to retrieve the first key from each object within the array:

var x = Object.keys(upgrades[0])[0];
console.log(x); // --> tree

Answer 2

To ensure your code functions correctly, make sure you are creating keys for the objects in the array rather than global variables. Start by correcting the syntax to create an array of objects structured like this:

var upgrades = [
  { tree: {price: 20, rate:0.5, owned:0} },
  { irr: {price: 80, rate:1, owned:0} },
  { press: {price: 150, rate:2, owned:0} },
  { cracker: {price: 400, rate:7, owned:0} },
  { gmo: {price: 1000, rate:10, owned:0} },
  { shack: {price: 1500, rate:13, owned:0} },
  { truck: {price: 2000, rate:14, owned:0} },
  { factory: {price: 5000, rate:18, owned:0} },
  { rr: {price: 9000, rate:25, owned:0} },
  { mGadget: {price: 15000, rate:30, owned:0} },
];

Once this is done, utilize Object.keys() to retrieve the first key from each object within the array:

var x = Object.keys(upgrades[0])[0];
console.log(x); // --> tree

Answer 3

Answer №2

Your array seems to be incorrect. There should not be identifiers for array elements. It should look like this:

var upgrades = [
 {price: 20, rate:0.5, owned:0},
 {price: 80, rate:1, owned:0},
 {price: 150, rate:2, owned:0},
 {price: 400, rate:7, owned:0}
];

Therefore, you cannot retrieve an element of the array by name; you must do so by index.

var x = upgrades[0]

If you wish to use named identifiers to access elements, then you should consider using objects instead of arrays.

var upgrades = {
    tree : {price: 20, rate:0.5, owned:0},
    irr : {price: 80, rate:1, owned:0},
    press : {price: 150, rate:2, owned:0},
    cracker : {price: 400, rate:7, owned:0}
}

 var x = upgrades.tree

To check by identifier in array:

Follow this example to retrieve array elements by identifier. Simply add a property to your objects in the upgrades array called 'identifier', and search for the specific identifier.

var upgrades = [
   {identifier : 'tree',price: 20, rate:0.5, owned:0},
   {identifier: 'tiger',price: 80, rate:1, owned:0}
];

var obj = upgrades.filter(function(elem,index){
   return elem.identifier == 'tree'
})
console.log(obj)

Answer 4

Your array seems to be incorrect. There should not be identifiers for array elements. It should look like this:

var upgrades = [
 {price: 20, rate:0.5, owned:0},
 {price: 80, rate:1, owned:0},
 {price: 150, rate:2, owned:0},
 {price: 400, rate:7, owned:0}
];

Therefore, you cannot retrieve an element of the array by name; you must do so by index.

var x = upgrades[0]

If you wish to use named identifiers to access elements, then you should consider using objects instead of arrays.

var upgrades = {
    tree : {price: 20, rate:0.5, owned:0},
    irr : {price: 80, rate:1, owned:0},
    press : {price: 150, rate:2, owned:0},
    cracker : {price: 400, rate:7, owned:0}
}

 var x = upgrades.tree

To check by identifier in array:

Follow this example to retrieve array elements by identifier. Simply add a property to your objects in the upgrades array called 'identifier', and search for the specific identifier.

var upgrades = [
   {identifier : 'tree',price: 20, rate:0.5, owned:0},
   {identifier: 'tiger',price: 80, rate:1, owned:0}
];

var obj = upgrades.filter(function(elem,index){
   return elem.identifier == 'tree'
})
console.log(obj)

Retrieve the title of an item stored within a list

Answer №1

Answer №2

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