minItems : Integer

minItems

Integer

An array instance is valid if its size is greater than, or equal to, the value of this keyword.

Value This keyword must be set to a zero or positive integer
Kind Assertion
Applies To Array
Dialect 2020-12
Changed In None
Introduced In Draft 1
Vocabulary Validation
Specification https://json-schema.org/draft/2020-12/json-schema-validation.html#section-6.4.2
Metaschema https://json-schema.org/draft/2020-12/meta/validation
Official Tests draft2020-12/minItems.json
Default 0
Annotation None
Affected By None
Affects None
Also See

The minItems keyword specifies the minimum number of items that must be present in an array. It can be used to define constraints on the size of an array, ensuring that it contains at least a certain number of elements.

  • An array is valid if it has at least the specified number of elements.

Examples

Schema with 'minItems' keyword Schema 
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "array",
  "minItems": 3
}
Valid An array instance with 3 or more elements is valid Instance 
[ 1, true, "hello" ]
Invalid An array instance with less than 3 elements is invalid Instance 
[ 1, "apple" ]
Schema with the 'minItems' and 'items' keywords Schema 
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "array",
  "items": { "type": "boolean" },
  "minItems": 2
}
Valid An array instance containing 2 or more items, which conform to the 'items' subschema, is valid Instance 
[ false, false, true ]
Invalid An array instance with less than 2 elements is invalid Instance 
[ false ]
Schema with the 'minItems', 'prefixItems' and 'contains' keywords Schema 
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "array",
  "prefixItems": [
    { "type": "number" },
    { "type": "string" }
  ],
  "contains": { "type": "boolean" },
  "minItems": 3
}
Valid An array instance containing 3 or more items, which successfully validates against 'prefixItems' and 'contains', is valid Instance 
[ 1, "John", false ]
Invalid An array instance with less than 3 elements is invalid Instance 
[ 1, "John" ]
Invalid First and second items should be number and string respectively Instance 
[ "John", 1, false ]