Arrays

Arrays in Internet Object

An array is represented by a pair of square brackets, which may contain zero or more values. It begins with an open square bracket ([ U+005B) and ends with a close square bracket (] U+005D). Each value is separated by commas (, U+002C). Essentially, an array is expressed as a sequence of values separated by commas enclosed in square brackets.

Syntax

Array Syntax

Array Structural Characters

Symbol	Characters	Unicode	Description
,	Comma	U+002C	Used as a value separator
[	Open Square Bracket	U+005B	Begins an array boundary
]	Close Square Bracket	U+005D	Closes an array boundary

Characteristics

Arrays can contain values of various types, including objects, other arrays, strings, numbers, boolean, and null.

Basic Arrays

A simple array of strings:

[one, two, three]

An array of objects:

[{ a, b, c }, {j, k, l}, { x, y, z }]

An array with mixed values:

[one, T, { a:10, b: -Inf, NaN }]

Multi-dimensional Arrays

Arrays can be nested to create multi-dimensional data structures.

Two-dimensional Arrays

Two-dimensional arrays represent rows and columns:

[[1, 1, 1], [1, 1, 1], [1, 1, 1]]

Three-dimensional Arrays

Three-dimensional arrays represent collections of two-dimensional arrays:

[
   [[10,20,30],[40,50,60],[70,80,90]], # elements of block 1
   [[11,22,33],[44,55,66],[77,88,99]], # elements of block 2
   [[12,23,34],[45,56,67],[78,89,90]]  # elements of block 3
]

Empty Arrays and Empty Values

An empty array is represented by a pair of square brackets with no values:

[]      # An empty array

Empty values between array elements are not permitted. To include a missing value, you must explicitly specify a valid value such as null. However, since the Internet Object specification neither assumes null by default nor supports undefined, any omission is strictly forbidden. Following are some examples of invalid array structures:

[a,b,] # Trailing comma
[a,,c] # Array with an empty value in the middle