An element in an array is present in another array or not

[lake]

I would like to know how to check whether an element in one array is present in another array or not?
I have tried arr1.every(item => arr2.includes(item)) in mapper snap. It complaints about list type does not have a method named every. I used sl.ensureArray function to ensure (arr1 and arr2) as arrays.

[Aleksandar_A · Accepted solution]

Hello @lake,

You can iterate through one of the arrays using either map or filter (depends on what you want as an output) and check if the current element is present in the second array.

Example input:

[
	{
		"arr1": [
			1,
			2,
			3,
			4,
			5,
			6
		],
		"arr2": [
			3,
			4,
			5,
			6,
			7,
			8
		]
	}
]

Using map:

$arr1.map(x => {"elem": x,"found": $arr2.indexOf(x) != -1})

"compare": [
			{
				"elem": 1,
				"found": false
			},
			{
				"elem": 2,
				"found": false
			},
			{
				"elem": 3,
				"found": true
			},
			{
				"elem": 4,
				"found": true
			},
			{
				"elem": 5,
				"found": true
			},
			{
				"elem": 6,
				"found": true
			}

Using filter:

$arr1.filter(x => $arr2.indexOf(x) != -1)

"present": [
			3,
			4,
			5,
			6
		]

You can refer to the attached pipeline and let me know if it helps you.

Regards,

Aleksandar.