What is the process for obtaining the final element in an array of objects when a particular character is present in the value of a key?

Question

What is the process for obtaining the final element in an array of objects when a particular character is present in the value of a key?

Given the following array:

arrOfOranges =
[{ "kerp": "thisThing", "time": "@ rocks 3"},
{ "kerp": "otherThing", "green": "blah"},
{ "kerp": "thisThing", "time": "(countriesToTheStart ^"},
{ "kerp": "anotherThing", "yellow": "row row"},
{ "kerp": "anotherThing", "yellow": "rigorous"},
{ "kerp": "thisThing", "time": ",,,,"}]

Each item in the array has the fixed structure:

[{kerp: ''}] that can be one of three values: thisThing, otherThing, or anotherThing. The second key for each object depends on the value of 'kerp'.

If kerp is 'thisThing', then the second key is 'time'. => { "kerp": "thisThing", "time": ""},

If kerp is 'otherThing', then the second key is 'green'. => { "kerp": "otherThing", "green": ""},

If kerp is 'anotherThing', then the second key is 'yellow'. => { "kerp": "anotherThing", "yellow": ""},

I am trying to extract the last item in the array with 'kerp': 'thisThing'. However, the value associated with the 'time' key must contain a letter.

In the given array, the last item has 'kerp': 'thisThing', but the 'time' does not contain a letter.

Therefore, I need to retrieve the item from arrOfOranges where it's the last item with kerp as thisThing and time containing letters in the value:

{"kerp": "thisThing", "time": "(countriesToTheStart ^"}

Here is my current approach:

if (arrOfOranges.filter(a=>a.kerp === "thisThing")) {
    // Checking if the time value contains any letters
    if(arrOfOranges.time.match(/[\w]+/g))  {
        return arrOfOranges.slice(-1)[0];
    }
}

However, this solution is not working as intended. How can I achieve the desired outcome?

javascript arrays json key-value

Answer 1

Answer №1

To ensure proper filtering, make sure the check stays within the filter function.

const arrOfOranges = [
  { "kerp": "thisThing", "time": "@ rocks 3"},
  { "kerp": "otherThing", "green": "blah"},
  { "kerp": "thisThing", "time": "(countriesToTheStart ^"},
  { "kerp": "anotherThing", "yellow": "row row"},
  { "kerp": "anotherThing", "yellow": "rigorous"},
  { "kerp": "thisThing", "time": ",,,,"}
 ]

const result = arrOfOranges.filter(orange => orange.kerp === "thisThing" && orange.time.match(/[\w]+/g));

console.log(result);

Answer 2

To ensure proper filtering, make sure the check stays within the filter function.

const arrOfOranges = [
  { "kerp": "thisThing", "time": "@ rocks 3"},
  { "kerp": "otherThing", "green": "blah"},
  { "kerp": "thisThing", "time": "(countriesToTheStart ^"},
  { "kerp": "anotherThing", "yellow": "row row"},
  { "kerp": "anotherThing", "yellow": "rigorous"},
  { "kerp": "thisThing", "time": ",,,,"}
 ]

const result = arrOfOranges.filter(orange => orange.kerp === "thisThing" && orange.time.match(/[\w]+/g));

console.log(result);

Answer 3

Answer №2

To reverse the order of your arrOfOranges, you can utilize the .reverse() method and then apply the .find() function on the reversed array. The find method will identify and return the first object for which the provided callback returns true. In the example below, I have set it to return true when the time key contains a word character represented by \w and when the kerp key matches "thisThing". It is important to note that I used .slice() before invoking .reverse() to avoid directly altering the original arrOfOranges array:

const arrOfOranges = [{ "kerp": "thisThing", "time": "@ rocks 3"}, { "kerp": "otherThing", "green": "blah"}, { "kerp": "thisThing", "time": "(countriesToTheStart ^"}, { "kerp": "anotherThing", "yellow": "row row"}, { "kerp": "anotherThing", "yellow": "rigorous"}, { "kerp": "thisThing", "time": ",,,,"];

const search = {kerp: "thisThing", key: "time"};
const res = arrOfOranges.slice().reverse().find(
  obj => obj.kerp === search.kerp && /\w/.test(obj[search.key])
);

console.log(res);

If you prefer a slightly more efficient method, you can opt for a traditional for loop that iterates backwards through the array:

const arrOfOranges = [{ "kerp": "thisThing", "time": "@ rocks 3"}, { "kerp": "otherThing", "green": "blah"}, { "kerp": "thisThing", "time": "(countriesToTheStart ^"}, { "kerp": "anotherThing", "yellow": "row row"}, { "kerp": "anotherThing", "yellow": "rigorous"}, { "kerp": "thisThing", "time": ",,,,"];

const search = {kerp: "thisThing", key: "time"};
function findObj(data, search) {
  for(let i = data.length-1; i >= 0; i--) {
    const curr = data[i];
    if(curr.kerp === search.kerp && /\w/.test(curr[search.key]))
      return curr;
  }
}

console.log(findObj(arrOfOranges, search));

Answer 4

To reverse the order of your arrOfOranges, you can utilize the .reverse() method and then apply the .find() function on the reversed array. The find method will identify and return the first object for which the provided callback returns true. In the example below, I have set it to return true when the time key contains a word character represented by \w and when the kerp key matches "thisThing". It is important to note that I used .slice() before invoking .reverse() to avoid directly altering the original arrOfOranges array:

const arrOfOranges = [{ "kerp": "thisThing", "time": "@ rocks 3"}, { "kerp": "otherThing", "green": "blah"}, { "kerp": "thisThing", "time": "(countriesToTheStart ^"}, { "kerp": "anotherThing", "yellow": "row row"}, { "kerp": "anotherThing", "yellow": "rigorous"}, { "kerp": "thisThing", "time": ",,,,"];

const search = {kerp: "thisThing", key: "time"};
const res = arrOfOranges.slice().reverse().find(
  obj => obj.kerp === search.kerp && /\w/.test(obj[search.key])
);

console.log(res);

If you prefer a slightly more efficient method, you can opt for a traditional for loop that iterates backwards through the array:

const arrOfOranges = [{ "kerp": "thisThing", "time": "@ rocks 3"}, { "kerp": "otherThing", "green": "blah"}, { "kerp": "thisThing", "time": "(countriesToTheStart ^"}, { "kerp": "anotherThing", "yellow": "row row"}, { "kerp": "anotherThing", "yellow": "rigorous"}, { "kerp": "thisThing", "time": ",,,,"];

const search = {kerp: "thisThing", key: "time"};
function findObj(data, search) {
  for(let i = data.length-1; i >= 0; i--) {
    const curr = data[i];
    if(curr.kerp === search.kerp && /\w/.test(curr[search.key]))
      return curr;
  }
}

console.log(findObj(arrOfOranges, search));

What is the process for obtaining the final element in an array of objects when a particular character is present in the value of a key?

Answer №1

Answer №2

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