Find the first duplicate element that appears in an array using a hash set for efficient lookup.
Code
Algorithmsecho "$arr" | jq 'group_by(.) | map(select(length > 1)) | .[0][0] // null'Parameters
Array to check (JSON)
Server
More Bash Snippets
Array Difference
Find elements in the first array that are not present in the second array.
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Count how many times each value appears in an array and return a frequency map.
Array Head
Get the first n elements of an array.
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Find common elements that exist in both arrays.
Array Tail
Get the last n elements of an array.
Array Union
Combine two arrays and remove duplicates to produce a union.