# Array An Internet Object array can be defined with the members such as `type`, `default`, `len`, `minLen`, `maxLen`, `optional` and `null`. Schema of the array TypeDef should be written as, ### TypeDef Schema ```yaml schema? : {[$type, $memberdef, [any]], default:[any]} default? : array, minLen? : {int, minLen: 0}, maxLen? : {int, minLen}, len? : {int, minLen: 0}, null? : {bool, F} optional? : {bool, F} type? : {string, choices:[array]} --- ``` The TypeDef schema ensures the validity of `array` MemberDefs. #### schema The first member of the internet object array is a schema. When the schema is defined all array items must be validated against the schema. The code snippet demonstrates how the array can be defined with the schema. ```yaml # An array that can hold any values a: [], # An array of number a: [number], # An array of address object c: [{street, city, state}], # A fixed sized array (len 5) of string that can accept maxLen of 10 characters d: {[{string, maxLen:10}], len: 5}, # A fixed sized array (len 5) of string e: {default: [], schema: {[string], len: 5}, optional: T} --- ``` #### default The next member in the `array` typedef is `default` . Here is how the default values can be defined for an array. ```yaml # An array with an [] default a: {array, default: [], optional: T}, # An array with a null default b: {[string], default: N, optional: T, null: T} --- ``` #### **minLen** The value of `minLen` must be a non-negative integer. The array instance is valid only if, number of items in the array will be greater than or equal to the value of `minLen`. The code snippet shows how to define `minLen` for an array. ```yaml # A variable sized array of string with minLen: 3 a: {[string], minLen: 3} --- ``` #### **maxLen** The value of `maxlen` must be a non-negative integer. The array instance is valid only if, number of items in the array will be less than or equal to the value of the `maxlen`. Here the code snippet shows how to define `maxLen` for an array. ```yaml # A variable sized array of string witn maxLen:5 a: {[string], maxlen: 5} --- ``` #### **len** The next member in the `array` typedef is length represented as `len` , it must be a non-negative integer. The Array instance is valid only if, the number of items in the array will be exactly equal to the value of `len`. Here is how the `len` can be defined for an array. ```yaml # A fixed sized array with length 5 a: {[string], len: 5} --- ``` {% hint style="info" %} The `len` has higher precedence over `minLen` and `maxLen` constraints. That is when the `len` is set, the implementations must ignore `minLen` and `maxLen` constraints. {% endhint %} #### **null** An array when set to `null` will accept null values. Here the code snippet demonstrates the way how an array can accept a null value. ```yaml # An array set to null a?*: {array, default: N} # An array that will accept any values. b: {[], null: T} --- ``` #### optional A member of an array type can be set to optional. Here a code snippet demonstrates different ways how an array can be set to optional ```yaml # Set an array to optional a?: [] b?: array # Assign optional value to an array using optional: T b: {[], optional: T} # Set an array to option using default and null c: {[], default: N, null: T, default: T} --- ``` #### **type** An array type can be specified as shown in the snippet below. ```yaml # Set an array type for a, b, c a: array b: {type: array} c: {type: array, schema:[number]} --- ``` ### Examples Some of the valid examples of members with array type are... ```yaml # Defining an array of numbers numArray: [number] --- [63, 45, 66, 80, 74] ``` ```yaml # Defining an array of strings stringArray: [string] --- [English, Maths, Physics, Computer Science] ``` ```yaml # An alphanumeric array with a schema alphaNumArray: {array, schema: {any, anyOf: [string, int]}} --- [1, a, 2, b, 3, c] ``` The above example can be simplified as, ```yaml tags: [string, int] --- [1, a, 2, b, 3, c] ``` An array can have mixed values as shown in the snippet below. ```yaml # An array that will accept mixed values mixedArray: [ ] --- [one, T, { a:10, b: -Inf, NaN } ] ``` ```yaml # Assigning default: [] to the array of string ~ optionalStringArray?: {[strings], default: [ ]} --- ~ [Eggs, Green salad] # String Array ~ # Default is empty array [] ``` ```yaml # Assigning default and schema to the array object?: {array, default: [{N, N}], schema: [{ header*, footer*}]} --- ~ [{Hello, World}] # array of object ~ # default is array of null object ``` ```yaml # A fixed sized array of string with len: 5 fixedSizedStringArray: {[string], len: 5} --- [ Wings of Fire, Ignited Minds, Indomitable Spirit, India 2020, Turning Points ] ``` ```yaml # A variable sized array of objects with maxLen: 4. address:{ [{street: string, city: string, zip: {string, len: 5}], maxLen: 4 } --- [ {Bond street, New York, 50001}, {X street, Hollywood, 30001}, {Maple street, Tennessee, 80007}, {Union street, Montclair, 45003} ] ``` ### Nested Arrays An array containing another array represents a nested array as shown in the code snippet. ```yaml # Nested array enggDepartment: [ {deptName: string, deptSubject: {[string], maxLen: 5}} ] --- [computer Science, {[data structure, Language Processing]}] ``` ### Multidimensional Array A multidimensional array is an array with more than one dimension. Two and three-dimensional arrays are called multidimensional arrays. Here is the code snippet that demonstrates how a multidimensional array is represented. ```yaml # Two-Dimensional array matrix: {[{[int], len:3}], len: 3} --- [[1, 1, 1], [1, 1, 1], [1, 1, 1]] ``` ```yaml # Three-Dimensional array matrix: {[[{[int], len:3}], len: 3], len: 3} --- [ [[5, 1, 2], [2, 2, 1], [8, 5, 1]], [[4, 1, 8], [4, 6, 2], [4, 0, 2]], [[9, 1, 5], [1, 8, 1], [4, 2, 2]] ] ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.internetobject.org/schema-definition-language/data-types/array.md?ask= ``` The question should be specific, self-contained, and written in natural language. 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