The filter function results in a blank array being returned

Question

The filter function results in a blank array being returned

I'm facing a dilemma, I have a constant defined as

export const STATUS = [{
  0: 'Draft',
  1: 'Sent',
  2: 'Processing',
  9: 'Processed',
  3: 'Scheduled',
  4: 'Filed',
  5: 'Suspended',
  6: 'Protocol Error',
  7: 'Processing Error',
  8: 'Reading Error',
}];

and I've been trying to retrieve the values using this method

public constantFormatter(params) {
    const status = STATUS.filter((p) => p === params.value);
}

but it keeps returning empty, and I can't figure out why. Has anyone else encountered this issue?

javascript arrays typescript

Answer 1

Answer №1

If you're looking to define a set of constants, an enum is the way to go:

export enum STATUS {
  Draft,
  Sent,
  Processing,
  Processed = 9, // Only these two are needed since enums auto-increment and this one was out of order
  Scheduled = 3,
  FiledAway,
  Suspended,
  "Protocol Error",
  "Processing Error",
  "Reading Error",
};

export function constantFormatter(params: {
  value: number
}): string {
  return STATUS[params.value];
}

Answer 2

If you're looking to define a set of constants, an enum is the way to go:

export enum STATUS {
  Draft,
  Sent,
  Processing,
  Processed = 9, // Only these two are needed since enums auto-increment and this one was out of order
  Scheduled = 3,
  FiledAway,
  Suspended,
  "Protocol Error",
  "Processing Error",
  "Reading Error",
};

export function constantFormatter(params: {
  value: number
}): string {
  return STATUS[params.value];
}

Answer 3

Answer №2

You have encountered an error while trying to retrieve a property called 'params' that does not exist.

The issue stems from having an array consisting of only one object, which lacks the specified 'params' property. To access an object using a variable value, you must use array notation (object[whatever]) instead of dot notation (object.whatever).

Consider the following example:

const STATUS = [{
  0: 'Draft',
  1: 'Sent',
  2: 'Processing',
  9: 'Processed',
  3: 'Scheduled',
  4: 'Filed',
  5: 'Suspended',
  6: 'Protocol Error',
  7: 'Processing Error',
  8: 'Read Error'
}];

function constantFormatter(params) {
    return STATUS[0][params];
}

console.log(constantFormatter(4));

Answer 4

You have encountered an error while trying to retrieve a property called 'params' that does not exist.

The issue stems from having an array consisting of only one object, which lacks the specified 'params' property. To access an object using a variable value, you must use array notation (object[whatever]) instead of dot notation (object.whatever).

Consider the following example:

const STATUS = [{
  0: 'Draft',
  1: 'Sent',
  2: 'Processing',
  9: 'Processed',
  3: 'Scheduled',
  4: 'Filed',
  5: 'Suspended',
  6: 'Protocol Error',
  7: 'Processing Error',
  8: 'Read Error'
}];

function constantFormatter(params) {
    return STATUS[0][params];
}

console.log(constantFormatter(4));

Answer 5

Answer №3

If you are unable to modify the original array, one way to access object values from it is by utilizing the Object.values() method.

const STATUSES = [{
  0: 'Draft',
  1: 'Submitted',
  2: 'Processing',
  9: 'Processed',
  3: 'Scheduled',
  4: 'Filed',
  5: 'Suspended',
  6: 'Protocol Error',
  7: 'Processing Error',
  8: 'Reading Error'
}];

console.log(Object.values(STATUSES[0]));

Answer 6

If you are unable to modify the original array, one way to access object values from it is by utilizing the Object.values() method.

const STATUSES = [{
  0: 'Draft',
  1: 'Submitted',
  2: 'Processing',
  9: 'Processed',
  3: 'Scheduled',
  4: 'Filed',
  5: 'Suspended',
  6: 'Protocol Error',
  7: 'Processing Error',
  8: 'Reading Error'
}];

console.log(Object.values(STATUSES[0]));

The filter function results in a blank array being returned

Answer №1

Answer №2

Answer №3

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