Javascript array.find() only finds within first instance

Question

I have the following object array:

var data = {};

data.type = {
    "types": [{
        "testA": {
            "testVar": "abc",
            "testContent": "contentA"
        }
    }, {
        "testB": {
            "testVar": "def",
            "testContent": "contentB"
        }
    }]
};

What I'm trying to do is find the value of testContent based on finding the object it belongs by searching it's parent and sibling:

/* within the data, find content where parent is testA and sibling testVar is "abc" */
var findSet = data.type.types.find(function(entry) {
    return entry['testA'].testVar === "abc";
});

console.log(findSet['testA'].testContent); /* returns string "contentA" as expected */

This works fine for first object but fails to find next object, giving error:

Cannot read property 'testVar' of undefined

var findSet = data.type.types.find(function(entry) {
    return entry['testB'].testVar === "def"; /* Cannot read property 'testVar' of undefined */
});

console.log(findSet['testB'].testContent);

How else could I find what's needed?

Here's a fiddle to test the output

Steeve Pitis · Accepted Answer · 2016-10-03 10:02:04Z

2

var data = {};

data.type = {
	"types": [{
    	"testA": {
        	"testVar": "abc",
            "testContent": "contentA"
        }
    }, {
    	"testB": {
        	"testVar": "def",
            "testContent": "contentB"
        }
    }]
};

var findSet = data.type.types.find(function(entry) {
    return entry['testA'] && entry['testA'].testVar === "abc";
});

console.log(findSet['testA'].testContent);

var findSet = data.type.types.find(function(entry) {
    return entry['testB'] && entry['testB'].testVar === "def"; /* Cannot read property 'testVar' of undefined */
});

console.log(findSet['testB'].testContent);

just check if your entry exist before testing his attribute.

answered Oct 3, 2016 at 10:02

Steeve Pitis

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1 Comment

StudioTime Over a year ago

Hmmm - I thought the whole point of .find() was to not have to do this - many thanks anyway

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