Different techniques to access values in a JSON array without relying on specific index positions

Question

Different techniques to access values in a JSON array without relying on specific index positions

After making a request to an API, I received a JSON array with various attributes. One of the attributes is "State" and my task is to extract all the "EventName"(s) where State: "PR". The user will select the state from a dropdown menu.

In order to achieve this, I want to avoid using index numbers to access each attribute individually in the array. Instead, I am looking for a more efficient way to gather all the values that match the selected state (in this case, "PR").

So far, my attempt to filter out only the "EventName" values for "PR" resulted in a list of all the event names rather than just those specific to "PR". The desired outcome is to have a list like

pr_list = ["Debby 2000", "Dean 2001", "Jeane 2004" ... "Maria 2017"];

pr_list = [];
for (i = 0; i < event_data.length; i++) {
  state_data = event_data[i].State;
  if (state_data === "PR") {
    console.log(event_data[i].EventName)
    pr_list.append(event_data[i].EventName);
  }
}

javascript arrays json parsing

Answer 1

Answer №1

To achieve this, you can utilize the combination of Array.filter() and Array.map():

filtered_results = data_array.filter(item => (item.Type === "example"));
example_list = filtered_results.map(item => item.Name);

In reference to your current code snippet, there is a mistake:

if (condition_variable = "example") { ... }

It should be corrected to:

if (condition_variable === "example") { ... }

(For more details, check out MDN documentation)

Answer 2

To achieve this, you can utilize the combination of Array.filter() and Array.map():

filtered_results = data_array.filter(item => (item.Type === "example"));
example_list = filtered_results.map(item => item.Name);

In reference to your current code snippet, there is a mistake:

if (condition_variable = "example") { ... }

It should be corrected to:

if (condition_variable === "example") { ... }

(For more details, check out MDN documentation)

Answer 3

Answer №2

To achieve this, you can leverage Array.filter() and Array.map() like so:

selectedEvents = event_data.filter(event => (event.State === "PR")).map(event => event.EventName)

For ensuring uniqueness, utilize a Set:

selectedEvents = [...new Set(event_data.filter(event => (event.State === "PR")).map(event => event.EventName))]

Answer 4

To achieve this, you can leverage Array.filter() and Array.map() like so:

selectedEvents = event_data.filter(event => (event.State === "PR")).map(event => event.EventName)

For ensuring uniqueness, utilize a Set:

selectedEvents = [...new Set(event_data.filter(event => (event.State === "PR")).map(event => event.EventName))]

Answer 5

Answer №3

Innovative Approach

let finalList = [];
const data = [{ Name: 'Item1', Category: 'A' }, { Name: 'Item2', Category: 'B' }];
for (let idx = 0; idx < data.length; idx += 1) {
  let item = data[idx];
  if (item.Category === 'A') {
    finalList.push(item.Name);
  }
}
console.log(finalList);

Revolutionary Method

const dataList = [{ Name: 'Item1', Category: 'A' }, { Name: 'Item2', Category: 'B' }];
const filteredList = dataList.filter((f) => {
  return f.Category &&
    f.Category === 'A';
}).map((m) => { return m.Name; });
console.log(filteredList);

Answer 6

Innovative Approach

let finalList = [];
const data = [{ Name: 'Item1', Category: 'A' }, { Name: 'Item2', Category: 'B' }];
for (let idx = 0; idx < data.length; idx += 1) {
  let item = data[idx];
  if (item.Category === 'A') {
    finalList.push(item.Name);
  }
}
console.log(finalList);

Revolutionary Method

const dataList = [{ Name: 'Item1', Category: 'A' }, { Name: 'Item2', Category: 'B' }];
const filteredList = dataList.filter((f) => {
  return f.Category &&
    f.Category === 'A';
}).map((m) => { return m.Name; });
console.log(filteredList);

Answer 7

Answer №4

To retrieve a list of events with the state as "PR," you can utilize the array.filter() function. Additionally, to extract all event IDs from the list, you can make use of the array.map() function.

var array = [
  {eventId: '1', State: 'PR'},
  {eventId: '2', State: 'AR'},
  {eventId: '3', State: 'PR'}
];

// Filter out events with State as PR
array = array.filter(function (event) {
  return event.State === "PR";
});

// Extract all eventIds into a new array
var eventIds = array.map(function (event) {
   return event.eventId
});

console.log('eventIds:', eventIds);

Answer 8

To retrieve a list of events with the state as "PR," you can utilize the array.filter() function. Additionally, to extract all event IDs from the list, you can make use of the array.map() function.

var array = [
  {eventId: '1', State: 'PR'},
  {eventId: '2', State: 'AR'},
  {eventId: '3', State: 'PR'}
];

// Filter out events with State as PR
array = array.filter(function (event) {
  return event.State === "PR";
});

// Extract all eventIds into a new array
var eventIds = array.map(function (event) {
   return event.eventId
});

console.log('eventIds:', eventIds);

Different techniques to access values in a JSON array without relying on specific index positions

Answer №1

Answer №2

Answer №3

Answer №4

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