An array is an ordered collection of values. Each value is called an element, and each element has a numeric position in the array, known as its index.
0, and the highest possible index is 4294967294 (), for a maximum as needed and there is no need to declare a fixed size for the array when you create it or to reallocate it when the size changes.
- For non sparse arrays, this property specifies the number of elements in the array.
- For sparse arrays,
lengthis larger than the index of all elements.