IDBKeyRange.includes()

Syntax

myIncludesResult = myKeyRange.includes('A');

Parameters

key

The key you want to check for in your key range. This can be any type.

Returns

A Boolean.

Exceptions

This method may raise a DOMException of the following type:

Example

var keyRangeValue = IDBKeyRange.bound('A', 'K', false, false);

var myResult = keyRangeValue.includes('F');
// Returns true

var myResult = keyRangeValue.includes('W');
// Returns false

Specification

Browser compatibility

[1] Behind a flag.

Polyfill

The includes() method was added in the second edition of the Indexed DB specification. For browsers that do not support it, the following polyfill can be used.

IDBKeyRange.prototype.includes = IDBKeyRange.prototype.includes || function(key) {
  var r = this, c;
  if (r.lower !== undefined) {
    c = indexedDB.cmp(key, r.lower)
    if (r.lowerOpen && c <= 0) return false;
    if (!r.lowerOpen && c < 0) return false;
  }
  if (r.upper !== undefined) {
    c = indexedDB.cmp(key, r.upper)
    if (r.upperOpen && c >= 0) return false;
    if (!r.upperOpen && c > 0) return false;
  }
  return true;
};

See also

• Using IndexedDB
• Starting transactions: IDBDatabase
• Using transactions: IDBTransaction
• Setting a range of keys: IDBKeyRange
• Retrieving and making changes to your data: IDBObjectStore
• Using cursors: IDBCursor
• Reference example: To-do Notifications (view example live.)