2.3 Indexed Access (Arrays)

>>>

var arr = ['a', 'b', 'c']

>>>

arr[0]

"a"

The array index syntax is used to access array elements by their position in the array. The elements are zero-indexed.

>>>

arr[5] = 'd'

"d"

Similar to objects, the assignment operator is used to modify or set new values in the array.

>>>

arr

["a", "b", "c", undefined, undefined, "d"]

If the index used in the assignment is beyond the current array boundaries, it is extended with new undefined elements as needed.

>>>

arr.length

The special length property will be automatically updated to reflect the number of elements currently in the array.

>>>

arr.length = 3

The length property can also be assigned a value, which will truncate or lengthen the array as needed.

>>>

arr

["a", "b", "c"]

>>>

arr.push('d')

The simplest way to add an element to the end of an array is to use the built-in push() method.

>>>

arr[arr.length] = 'e'

"e"

Another way to add an element uses the length property.

>>>

arr

["a", "b", "c", "d", "e"]

>>>

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