Array.filter method returns undefined error when accessing object property in Zapier

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1

I need help with parsing JSON data from a webhook in my Zapier automation. I’m getting an error that says the property I’m trying to access is undefined.

Basically I have webhook data that contains an array of objects and I want to extract a specific ID based on matching a text value. Here’s what I’m working with:

const response = JSON.parse(inputData.payload);
return {
  response,
  TargetId: response.items.filter(
    item => item.title === inputData.searchText)[0].id
};

My webhook sends this JSON structure:

{"items":
[{"id":9876543210123456,"gid":"9876543210123456","title":"Johnson, Michael","type":"project"},
{"id":9876543187654321,"gid":"9876543187654321","title":"Contract Review:","type":"project"},
{"id":9876543298765432,"gid":"9876543298765432","title":"Project Completion:","type":"project"},
{"id":9876543176543210,"gid":"9876543176543210","title":"Initial Planning:","type":"project"},
{"id":9876543265432109,"gid":"9876543265432109","title":"Development Phase:","type":"project"}]}

I want to match the title field against searchText variable from a previous Zapier step. If searchText contains “Development Phase” I expect to get the ID “9876543265432109” but instead I get undefined property error. What am I doing wrong here?

2

This happens because Zapier often sends text with hidden whitespace or encoding issues. I’ve hit this exact problem with webhook data before. Try normalizing both strings first - trim whitespace and convert to lowercase. Use item.title.trim().toLowerCase().includes(inputData.searchText.trim().toLowerCase()) instead of strict equality. Also wrap everything in a try-catch block since Zapier’s error handling is pretty flaky. That undefined error means your filter’s returning an empty array, so the match isn’t working even though the data looks right.

3

Your filter’s returning an empty array when there’s no match, so you’re trying to grab index [0] from nothing, which is breaking it. Instead of using filter, consider using find() since you only want one result anyway. Here’s a modification for your code:

const response = JSON.parse(inputData.payload);
const foundItem = response.items.find(item => item.title === inputData.searchText);
return {
  response,
  TargetId: foundItem ? foundItem.id : null
};

This adjustment prevents undefined errors and provides proper fallback handling. Additionally, ensure your searchText matches exactly, including spaces and punctuation.

4

your filter isn’t finding a match, so [0] is trying to access undefined. add some debugging first - console.log the searchText and check if it exactly matches “Development Phase:”. i noticed your JSON has a colon after it, but you said you’re searching without one. that’s probly your issue.

5

Debugging webhook data parsing in Zapier is a nightmare. Those undefined errors and wonky string matching just kill productivity.

I jumped to Latenode after hitting this wall too many times. You get a real JavaScript environment where debugging actually works, plus error handling that doesn’t spit out cryptic garbage.

Set up the same webhook trigger, then use their code node for array filtering with proper error checking. The visual debugger shows you exactly what’s in your searchText variable and what the API response looks like at each step.

Array manipulation is way better too. No more wrestling with filter methods and undefined access - their data transformation nodes handle edge cases automatically.

Moved three automations from Zapier last month and haven’t looked back. Webhook processing is rock solid and when something breaks, you know why.

Check it out: https://latenode.com