How to Determine the Length of a Subarray in JavaScript

Question

How to Determine the Length of a Subarray in JavaScript

I am working with a JSON element that contains nested arrays:

json = [
        {
            "category": "Electronic",
            "param": "param1",
            "subMenu": [
                {
                    "subCategory": "Audio & Hifi",
                    "param": "param1-1",
                    "subMenu2": [
                        {
                            "type": "JVC",
                            "param": "param1-1-1"
                        },
                        {
                            "type": "Kennwood",
                            "param": "param1-1-2"
                        },
                        {
                            "type": "Sony",
                            "param": "param1-1-3"
                        },
                        {
                            "type": "Blaupunkt",
                            "param": "param1-1-4"
                        }
                    ]
                }]}]

I need to retrieve the length of the subarrays subMenu and subMenu2 for a specific function but have not found a suitable solution yet.

I have tried using a loop with

for (var i = 0; i < array.length; i++)

and

for (var i = 0; i < subMenu.length; i++)

but it did not give me the correct lengths. It was limited by the length of the main array.

You can see the issue in action here: https://jsfiddle.net/pp4t9nw2/4/

If anyone has a solution to this problem, I would greatly appreciate it.

javascript arrays json

Answer 1

Answer №1

If you want to nest loops within submenus, it's a good idea to use different variables for each loop. Here's an example:

for (var i = 0; i < json.length; i++) {
    for (var j = 0; j < json[i].subMenu.length; j++) {
        for (var k = 0; k < json[i].subMenu[j].subMenu2.length; k++) {
            let item = json[i].subMenu[j].subMenu2[k];
            // item.type available
        }
    }
}

Answer 2

If you want to nest loops within submenus, it's a good idea to use different variables for each loop. Here's an example:

for (var i = 0; i < json.length; i++) {
    for (var j = 0; j < json[i].subMenu.length; j++) {
        for (var k = 0; k < json[i].subMenu[j].subMenu2.length; k++) {
            let item = json[i].subMenu[j].subMenu2[k];
            // item.type available
        }
    }
}

Answer 3

Answer №2

If you're looking to find the number of elements in the main subMenu, you can access it by using json[0].subMenu.length.

Iterate through the json object (not an array as mentioned in your code) and for each element, you can retrieve its subMenu length by accessing json[iterator].subMenu.length.

To loop through subMenu2, you will need a nested loop using a different iterator variable to avoid conflicts.

Answer 4

If you're looking to find the number of elements in the main subMenu, you can access it by using json[0].subMenu.length.

Iterate through the json object (not an array as mentioned in your code) and for each element, you can retrieve its subMenu length by accessing json[iterator].subMenu.length.

To loop through subMenu2, you will need a nested loop using a different iterator variable to avoid conflicts.

Answer 5

Answer №3

When working with this scenario, it is important to correctly reference subMenu2. For instance: json.subMenu.subMenu2.length

However, it is worth noting that subMenu itself does not possess a length attribute, as it only contains subMenu2.

I trust this information has been beneficial to you.

Answer 6

When working with this scenario, it is important to correctly reference subMenu2. For instance: json.subMenu.subMenu2.length

However, it is worth noting that subMenu itself does not possess a length attribute, as it only contains subMenu2.

I trust this information has been beneficial to you.

How to Determine the Length of a Subarray in JavaScript

Answer №1

Answer №2

Answer №3

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