findIndex.md

arrays.findIndex

findIndex(array, predicate, [thisArg])

FindIndex method returns the value of First element at which a provided function is true, or -1 if no elements in the array satisfy the function.

Arguments

1. array (Array): input array
2. predicate (Function): to be run against each element of the array
3. [thisArg] (*): this argument in the function

Returns

(*): value of element that satisfied function.

Example

const result = arrays.findIndex([5, 12, 8, 130, 44], (x) => x < 10);
console.log(result);
> 0

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