The findIndex() method of {{jsxref("Array")}} instances returns the index of the first element in an array that satisfies the provided testing function. If no elements satisfy the testing function, -1 ...

JavaScript’s arrays can hold heterogeneous types, change size on the fly, and readily insert or remove elements. Traditional methods like slice, splice, and push/pop do this by operating on the array ...

The find() method of {{jsxref("Array")}} instances returns the first element in the provided array that satisfies the provided testing function. If no values satisfy the testing function, ...