Array iteration methods

The filter() method of Array instances creates a shallow copy of a portion of a given array, filtered down to just the elements from the given array that pass the test implemented by the provided function.

The forEach() method of Array instances executes a provided function once for each array element.

The indexOf() method of Array instances returns the first index at which a given element can be found in the array, or -1 if it is not present.

The lastIndexOf() method of Array instances returns the last index at which a given element can be found in the array, or -1 if it is not present. The array is searched backwards, starting at fromIndex.

The map() method of Array instances creates a new array populated with the results of calling a provided function on every element in the calling array.

The reduce() method of Array instances executes a user-supplied "reducer" callback function on each element of the array, in order, passing in the return value from the calculation on the preceding element. The final result of running the reducer across all elements of the array is a single value.

The reduceRight() method of Array instances applies a function against an accumulator and each value of the array (from right-to-left) to reduce it to a single value.

The some() method of Array instances returns true if it finds an element in the array that satisfies the provided testing function. Otherwise, it returns false.